[syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    8de1e7afcc1c Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1126f190e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=122a2560e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=136e08df680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0f00907f9764/disk-8de1e7af.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0502fe78c60d/vmlinux-8de1e7af.xz
kernel image: https://storage.googleapis.com/syzbot-assets/192135168cc0/Image-8de1e7af.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:777 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
Write of size 4 at addr ffff0000dba59080 by task kworker/0:1/10

CPU: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:475
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 kasan_check_range+0x254/0x294 mm/kasan/generic.c:187
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:193 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

Allocated by task 6180:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1026 [inline]
 __kmalloc+0xcc/0x1b8 mm/slab_common.c:1039
 kmalloc include/linux/slab.h:603 [inline]
 sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2090
 sk_alloc+0x44/0x3f4 net/core/sock.c:2143
 bt_sock_alloc+0x4c/0x32c net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:495 [inline]
 sco_sock_create+0xbc/0x31c net/bluetooth/sco.c:526
 bt_sock_create+0x14c/0x248 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x43c/0x884 net/socket.c:1569
 sock_create net/socket.c:1620 [inline]
 __sys_socket_create net/socket.c:1657 [inline]
 __sys_socket+0x134/0x340 net/socket.c:1708
 __do_sys_socket net/socket.c:1722 [inline]
 __se_sys_socket net/socket.c:1720 [inline]
 __arm64_sys_socket+0x7c/0x94 net/socket.c:1720
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Freed by task 6179:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522
 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0x2ac/0x480 mm/slub.c:3822
 kfree+0xb8/0x19c mm/slab_common.c:1075
 sk_prot_free net/core/sock.c:2126 [inline]
 __sk_destruct+0x4c0/0x770 net/core/sock.c:2218
 sk_destruct net/core/sock.c:2233 [inline]
 __sk_free+0x37c/0x4e8 net/core/sock.c:2244
 sk_free+0x60/0xc8 net/core/sock.c:2255
 sock_put include/net/sock.h:1989 [inline]
 sco_sock_kill+0xfc/0x1b4 net/bluetooth/sco.c:426
 sco_sock_release+0x1fc/0x2c0 net/bluetooth/sco.c:1256
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

The buggy address belongs to the object at ffff0000dba59000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff0000dba59000, ffff0000dba59800)

The buggy address belongs to the physical page:
page:00000000f24a79df refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ba58
head:00000000f24a79df order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000840 ffff0000c0002000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000dba58f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000dba59000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000dba59080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000dba59100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000dba59180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 10 at lib/refcount.c:25 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Tainted: G    B              6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
lr : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
sp : ffff800092d57af0
x29: ffff800092d57af0 x28: 1fffe0001a9b5a4a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d4dad250 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000002
x20: ffff0000dba59080 x19: ffff8000910a2000 x18: ffff800092d57800
x17: 0000000000000000 x16: ffff80008a71b23c x15: 0000000000000001
x14: 1ffff000125aaeb0 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000000 x9 : c0b0806111008b00
x8 : c0b0806111008b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800092d573d8 x4 : ffff80008e4210a0 x3 : ffff800082b180c4
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x19c/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 29659
hardirqs last  enabled at (29659): [<ffff80008a719090>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (29659): [<ffff80008a719090>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (29658): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (19646): [<ffff800080021894>] softirq_handle_end kernel/softirq.c:399 [inline]
softirqs last  enabled at (19646): [<ffff800080021894>] __do_softirq+0xac0/0xd54 kernel/softirq.c:582
softirqs last disabled at (19597): [<ffff80008002aadc>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 10 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Tainted: G    B   W          6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
sp : ffff800092d57af0
x29: ffff800092d57af0 x28: 1fffe0001a9b5a4a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d4dad250 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000003
x20: ffff0000dba59080 x19: ffff8000910a2000 x18: ffff800092d57800
x17: 0000000000000000 x16: ffff80008a71b23c x15: 0000000000000001
x14: 1fffe0003682f032 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : c0b0806111008b00
x8 : c0b0806111008b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800092d573d8 x4 : ffff80008e4210a0 x3 : ffff8000805a359c
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 sock_put include/net/sock.h:1988 [inline]
 sco_sock_timeout+0x1b0/0x25c net/bluetooth/sco.c:100
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 29659
hardirqs last  enabled at (29659): [<ffff80008a719090>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (29659): [<ffff80008a719090>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (29658): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (19646): [<ffff800080021894>] softirq_handle_end kernel/softirq.c:399 [inline]
softirqs last  enabled at (19646): [<ffff800080021894>] __do_softirq+0xac0/0xd54 kernel/softirq.c:582
softirqs last disabled at (19597): [<ffff80008002aadc>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
---[ end trace 0000000000000000 ]---


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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If the report is already addressed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com

Tested on:

commit:         7475e51b Merge tag 'net-6.7-rc2' of git://git.kernel.o..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=17b8635b680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=696dc362ad4818c4
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

net/bluetooth/sco.c:418:26: error: static assertion failed due to requirement '__builtin_types_compatible_p(struct sock, struct sock *) || __builtin_types_compatible_p(struct sock, void)': pointer type mismatch in container_of()


Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1417b23f680000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in hci_conn_drop

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1375 [inline]
BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x2bc include/net/bluetooth/hci_core.h:1523
Write of size 4 at addr ffff0000c892c010 by task syz-executor.0/6752

CPU: 0 PID: 6752 Comm: syz-executor.0 Not tainted 6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:475
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 kasan_check_range+0x254/0x294 mm/kasan/generic.c:187
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1375 [inline]
 hci_conn_drop+0x34/0x2bc include/net/bluetooth/hci_core.h:1523
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Allocated by task 6753:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 kmalloc_trace+0x70/0x88 mm/slab_common.c:1122
 kmalloc include/linux/slab.h:599 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 hci_conn_add+0xcc/0x1210 net/bluetooth/hci_conn.c:957
 hci_connect_sco+0x94/0x2bc net/bluetooth/hci_conn.c:1701
 sco_connect net/bluetooth/sco.c:265 [inline]
 sco_sock_connect+0x270/0x8bc net/bluetooth/sco.c:590
 __sys_connect_file net/socket.c:2050 [inline]
 __sys_connect+0x268/0x290 net/socket.c:2067
 __do_sys_connect net/socket.c:2077 [inline]
 __se_sys_connect net/socket.c:2074 [inline]
 __arm64_sys_connect+0x7c/0x94 net/socket.c:2074
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Freed by task 5665:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522
 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0x2ac/0x480 mm/slub.c:3822
 kfree+0xb8/0x19c mm/slab_common.c:1075
 bt_link_release+0x20/0x30 net/bluetooth/hci_sysfs.c:16
 device_release+0x8c/0x1ac
 kobject_cleanup lib/kobject.c:682 [inline]
 kobject_release lib/kobject.c:716 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1c4/0x3c4 lib/kobject.c:733
 put_device+0x28/0x40 drivers/base/core.c:3732
 hci_conn_put include/net/bluetooth/hci_core.h:1506 [inline]
 hci_conn_cleanup net/bluetooth/hci_conn.c:178 [inline]
 hci_conn_del+0x78c/0xabc net/bluetooth/hci_conn.c:1156
 hci_conn_failed+0x204/0x2c0 net/bluetooth/hci_conn.c:1252
 hci_abort_conn_sync+0x688/0xe38 net/bluetooth/hci_sync.c:5428
 abort_conn_sync+0x5c/0x8c net/bluetooth/hci_conn.c:2910
 hci_cmd_sync_work+0x1cc/0x34c net/bluetooth/hci_sync.c:306
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

The buggy address belongs to the object at ffff0000c892c000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 16 bytes inside of
 freed 4096-byte region [ffff0000c892c000, ffff0000c892d000)

The buggy address belongs to the physical page:
page:00000000c7691a02 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x108928
head:00000000c7691a02 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000840 ffff0000c0002140 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000c892bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000c892bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000c892c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff0000c892c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000c892c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
ODEBUG: assert_init not available (active state 0) object: 000000000c51268a object type: timer_list hint: hci_conn_timeout+0x0/0x1e8 net/bluetooth/hci_conn.c:928
WARNING: CPU: 0 PID: 6752 at lib/debugobjects.c:517 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
Modules linked in:
CPU: 0 PID: 6752 Comm: syz-executor.0 Tainted: G    B              6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
lr : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
sp : ffff800096f67790
x29: ffff800096f67790 x28: dfff800000000000 x27: ffff700012decf00
x26: dfff800000000000 x25: dfff800000000000 x24: ffff0000c892c390
x23: ffff80008ad651a0 x22: ffff800089881d98 x21: ffff80008a89c360
x20: 0000000000000000 x19: ffff80008ad64cc0 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008a668980 x15: 0000000000000001
x14: 1ffff00012dece0c x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000000 x9 : c73071275ea21a00
x8 : c73071275ea21a00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096f67078 x4 : ffff80008e4210a0 x3 : ffff8000803639bc
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
 debug_object_assert_init+0x318/0x3c8 lib/debugobjects.c:941
 debug_timer_assert_init kernel/time/timer.c:792 [inline]
 debug_assert_init kernel/time/timer.c:837 [inline]
 __timer_delete+0xac/0x2f8 kernel/time/timer.c:1321
 timer_delete+0x24/0x34 kernel/time/timer.c:1361
 del_timer include/linux/timer.h:213 [inline]
 try_to_grab_pending+0x8c/0x618 kernel/workqueue.c:1564
 __cancel_work+0xb0/0x2a8 kernel/workqueue.c:3582
 cancel_delayed_work+0x24/0x38 kernel/workqueue.c:3620
 hci_conn_drop+0x150/0x2bc include/net/bluetooth/hci_core.h:1548
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 15717
hardirqs last  enabled at (15717): [<ffff80008a719110>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (15717): [<ffff80008a719110>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (15716): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (15458): [<ffff8000888c272c>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (15458): [<ffff8000888c272c>] lock_sock_nested+0xcc/0x11c net/core/sock.c:3512
softirqs last disabled at (15456): [<ffff8000888c26d4>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (15456): [<ffff8000888c26d4>] lock_sock_nested+0x74/0x11c net/core/sock.c:3508
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6752 at kernel/workqueue.c:1939 __queue_delayed_work kernel/workqueue.c:1939 [inline]
WARNING: CPU: 0 PID: 6752 at kernel/workqueue.c:1939 queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
Modules linked in:
CPU: 0 PID: 6752 Comm: syz-executor.0 Tainted: G    B   W          6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __queue_delayed_work kernel/workqueue.c:1939 [inline]
pc : queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
lr : __queue_delayed_work kernel/workqueue.c:1939 [inline]
lr : queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
sp : ffff800096f67af0
x29: ffff800096f67af0 x28: 1fffe0001a828d80 x27: dfff800000000000
x26: 0000000000000000 x25: ffff0000c892c3a8 x24: ffff0000cb635400
x23: 0000000000000000 x22: ffff0000c892c348 x21: 0000000000000008
x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008a71b2bc x15: ffff600019125869
x14: 1fffe00019125869 x13: 00000000000000fb x12: ffffffffffffffff
x11: 0000000000000001 x10: 0000000000000000 x9 : 0000000000000000
x8 : ffff0000d5f21bc0 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080221e68
x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000000
Call trace:
 __queue_delayed_work kernel/workqueue.c:1939 [inline]
 queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
 queue_delayed_work include/linux/workqueue.h:569 [inline]
 hci_conn_drop+0x198/0x2bc include/net/bluetooth/hci_core.h:1549
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 15717
hardirqs last  enabled at (15717): [<ffff80008a719110>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (15717): [<ffff80008a719110>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (15716): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (15458): [<ffff8000888c272c>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (15458): [<ffff8000888c272c>] lock_sock_nested+0xcc/0x11c net/core/sock.c:3512
softirqs last disabled at (15456): [<ffff8000888c26d4>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (15456): [<ffff8000888c26d4>] lock_sock_nested+0x74/0x11c net/core/sock.c:3508
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
ODEBUG: activate not available (active state 0) object: 000000002ed6b31e object type: work_struct hint: hci_conn_timeout+0x0/0x1e8 net/bluetooth/hci_conn.c:928
WARNING: CPU: 0 PID: 6752 at lib/debugobjects.c:517 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
Modules linked in:
CPU: 0 PID: 6752 Comm: syz-executor.0 Tainted: G    B   W          6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
lr : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
sp : ffff800096f67870
x29: ffff800096f67870 x28: dfff800000000000 x27: ffff700012decf1c
x26: ffff0000e2130b78 x25: dfff800000000000 x24: ffff0000c892c348
x23: ffff80008ad651a0 x22: ffff800089881d98 x21: ffff80008a8710a0
x20: 0000000000000000 x19: ffff80008ad64c40 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008a71b2bc x15: 0000000000000001
x14: 1fffe0003682f032 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000002 x10: 0000000000000000 x9 : c73071275ea21a00
x8 : c73071275ea21a00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096f67158 x4 : ffff80008e4210a0 x3 : ffff8000805a359c
x2 : 0000000000000001 x1 : 0000000000000002 x0 : 0000000000000000
Call trace:
 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
 debug_object_activate+0x600/0x7e0 lib/debugobjects.c:760
 debug_work_activate kernel/workqueue.c:572 [inline]
 insert_work+0x4c/0x2d4 kernel/workqueue.c:1644
 __queue_work+0xcf4/0x1338 kernel/workqueue.c:1799
 __queue_delayed_work kernel/workqueue.c:1950 [inline]
 queue_delayed_work_on+0x1f4/0x2e4 kernel/workqueue.c:1986
 queue_delayed_work include/linux/workqueue.h:569 [inline]
 hci_conn_drop+0x198/0x2bc include/net/bluetooth/hci_core.h:1549
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 15717
hardirqs last  enabled at (15717): [<ffff80008a719110>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (15717): [<ffff80008a719110>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (15716): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (15458): [<ffff8000888c272c>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (15458): [<ffff8000888c272c>] lock_sock_nested+0xcc/0x11c net/core/sock.c:3512
softirqs last disabled at (15456): [<ffff8000888c26d4>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (15456): [<ffff8000888c26d4>] lock_sock_nested+0x74/0x11c net/core/sock.c:3508
---[ end trace 0000000000000000 ]---


Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=13ba3458e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=150ac400e80000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com

Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14ace3d4e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15faf610e80000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:777 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
Write of size 4 at addr ffff0000db795080 by task kworker/0:3/6101

CPU: 0 PID: 6101 Comm: kworker/0:3 Not tainted 6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events sco_sock_timeout
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:475
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 kasan_check_range+0x254/0x294 mm/kasan/generic.c:187
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:193 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

Allocated by task 6617:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1026 [inline]
 __kmalloc+0xcc/0x1b8 mm/slab_common.c:1039
 kmalloc include/linux/slab.h:603 [inline]
 sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2090
 sk_alloc+0x44/0x3f4 net/core/sock.c:2143
 bt_sock_alloc+0x4c/0x32c net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:496 [inline]
 sco_sock_create+0xbc/0x31c net/bluetooth/sco.c:527
 bt_sock_create+0x14c/0x248 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x43c/0x884 net/socket.c:1569
 sock_create net/socket.c:1620 [inline]
 __sys_socket_create net/socket.c:1657 [inline]
 __sys_socket+0x134/0x340 net/socket.c:1708
 __do_sys_socket net/socket.c:1722 [inline]
 __se_sys_socket net/socket.c:1720 [inline]
 __arm64_sys_socket+0x7c/0x94 net/socket.c:1720
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Freed by task 6617:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522
 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0x2ac/0x480 mm/slub.c:3822
 kfree+0xb8/0x19c mm/slab_common.c:1075
 sk_prot_free net/core/sock.c:2126 [inline]
 __sk_destruct+0x4c0/0x770 net/core/sock.c:2218
 sk_destruct net/core/sock.c:2233 [inline]
 __sk_free+0x37c/0x4e8 net/core/sock.c:2244
 sk_free+0x60/0xc8 net/core/sock.c:2255
 sock_put include/net/sock.h:1989 [inline]
 sco_sock_kill+0xfc/0x1b4 net/bluetooth/sco.c:427
 sco_sock_release+0x1fc/0x2c0 net/bluetooth/sco.c:1257
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 ____fput+0x20/0x30 fs/file_table.c:412
 task_work_run+0x230/0x2e0 kernel/task_work.c:180
 get_signal+0x13f4/0x15ec kernel/signal.c:2668
 do_signal arch/arm64/kernel/signal.c:1249 [inline]
 do_notify_resume+0x3bc/0x393c arch/arm64/kernel/signal.c:1302
 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:144 [inline]
 el0_svc+0x9c/0x158 arch/arm64/kernel/entry-common.c:679
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

The buggy address belongs to the object at ffff0000db795000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff0000db795000, ffff0000db795800)

The buggy address belongs to the physical page:
page:0000000058a39b68 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000db797000 pfn:0x11b790
head:0000000058a39b68 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000840 ffff0000c0002000 ffff0000c0000948 fffffc0003359410
raw: ffff0000db797000 0000000000080006 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000db794f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000db795000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000db795080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000db795100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000db795180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 6101 at lib/refcount.c:25 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 6101 Comm: kworker/0:3 Tainted: G    B              6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
lr : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
sp : ffff800096c47af0
x29: ffff800096c47af0 x28: 1fffe0001abfc00a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d5fe0050 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000002
x20: ffff0000db795080 x19: ffff8000910a2000 x18: ffff800096c47800
x17: 0000000000000000 x16: ffff80008a6688c0 x15: 0000000000000001
x14: 1ffff00012d88e78 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000000 x9 : 345179c02a25c000
x8 : 345179c02a25c000 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096c473d8 x4 : ffff80008e4210a0 x3 : ffff8000803639bc
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x19c/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 5571
hardirqs last  enabled at (5571): [<ffff80008a719050>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (5571): [<ffff80008a719050>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (5570): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (5414): [<ffff800085cd6e40>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report_work+0x620/0x924 drivers/net/netdevsim/dev.c:850
softirqs last disabled at (5412): [<ffff800085cd6dbc>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:816 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report_work+0x59c/0x924 drivers/net/netdevsim/dev.c:850
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 6101 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 6101 Comm: kworker/0:3 Tainted: G    B   W          6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
sp : ffff800096c47af0
x29: ffff800096c47af0 x28: 1fffe0001abfc00a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d5fe0050 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000003
x20: ffff0000db795080 x19: ffff8000910a2000 x18: 1fffe0003682efce
x17: 0000000000000000 x16: ffff80008a71b1fc x15: 0000000000000001
x14: 1ffff00012d88eb0 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 345179c02a25c000
x8 : 345179c02a25c000 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096c473d8 x4 : ffff80008e4210a0 x3 : ffff800082b180c4
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 sock_put include/net/sock.h:1988 [inline]
 sco_sock_timeout+0x1b0/0x25c net/bluetooth/sco.c:100
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 5571
hardirqs last  enabled at (5571): [<ffff80008a719050>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (5571): [<ffff80008a719050>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (5570): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (5414): [<ffff800085cd6e40>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report_work+0x620/0x924 drivers/net/netdevsim/dev.c:850
softirqs last disabled at (5412): [<ffff800085cd6dbc>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:816 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report_work+0x59c/0x924 drivers/net/netdevsim/dev.c:850
---[ end trace 0000000000000000 ]---


Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14336477680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=139b4e48e80000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

syzbot has bisected this issue to:

commit 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3
Author: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date:   Thu Mar 30 21:15:50 2023 +0000

    Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=179a65d2e80000
start commit:   bee0e7762ad2 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=145a65d2e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=105a65d2e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b50bd31249191be8
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1504504ae80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14685f54e80000

Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
Fixes: 9a8ec9e8ebb5 ("Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[xingwei lee]

Hello

I reproduced both two bugs with relatively stable poc, hope it helps.
In my prograss, I meet three bugs titles are respectively

KASAN: slab-out-of-bounds Write in sco_sock_timeout
https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
KASAN: slab-use-after-free Write in sco_conn_del
https://syzkaller.appspot.com/bug?extid=6b9277cad941daf126a2
KASAN: wild-memory-access Read in lock_sock_nested may be new.

My reproducer can crash in the latest net tree HEAD:
1ae4cd3cbdd08287c56c4cc816ebf05eb6681a0f and also the latest upstream
mainline.
However, when I try to execute their reproducer, the crash seems the
same, this makes me very likely that they are maybe the same bug.

TITLE: KASAN: slab-use-after-free Write in sco_sock_timeout
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write
home/dubbo/net/./include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed
home/dubbo/net/./include/linux/atomic/atomic-instrumented.h:252
[inline]
BUG: KASAN: slab-use-after-free in __refcount_add
home/dubbo/net/./include/linux/refcount.h:193 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc
home/dubbo/net/./include/linux/refcount.h:250 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc
home/dubbo/net/./include/linux/refcount.h:267 [inline]
BUG: KASAN: slab-use-after-free in sock_hold
home/dubbo/net/./include/net/sock.h:777 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x68/0x2b0
home/dubbo/net/net/bluetooth/sco.c:88
Write of size 4 at addr ffff888156922080 by task kworker/1:0/8390
CPU: 1 PID: 8390 Comm: kworker/1:0 Not tainted 6.7.0-rc4-00141-g1ae4cd3cbdd0 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.2-debian-1.16.2-1 04/01/4
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack home/dubbo/net/lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 home/dubbo/net/lib/dump_stack.c:106
 print_address_description home/dubbo/net/mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 home/dubbo/net/mm/kasan/report.c:475
 kasan_report+0xda/0x110 home/dubbo/net/mm/kasan/report.c:588
 check_region_inline home/dubbo/net/mm/kasan/generic.c:181 [inline]
 kasan_check_range+0xef/0x190 home/dubbo/net/mm/kasan/generic.c:187
 instrument_atomic_read_write
home/dubbo/net/./include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed
home/dubbo/net/./include/linux/atomic/atomic-instrumented.h:252
[inline]
 __refcount_add home/dubbo/net/./include/linux/refcount.h:193 [inline]
 __refcount_inc home/dubbo/net/./include/linux/refcount.h:250 [inline]
 refcount_inc home/dubbo/net/./include/linux/refcount.h:267 [inline]
 sock_hold home/dubbo/net/./include/net/sock.h:777 [inline]
 sco_sock_timeout+0x68/0x2b0 home/dubbo/net/net/bluetooth/sco.c:88
 process_one_work+0x830/0x1550 home/dubbo/net/kernel/workqueue.c:2627
 process_scheduled_works home/dubbo/net/kernel/workqueue.c:2700 [inline]
 worker_thread+0x8b9/0x1290 home/dubbo/net/kernel/workqueue.c:2781
 kthread+0x33c/0x440 home/dubbo/net/kernel/kthread.c:388
 ret_from_fork+0x45/0x80 home/dubbo/net/arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 home/dubbo/net/arch/x86/entry/entry_64.S:242
 </TASK>
Allocated by task 8208:
 kasan_save_stack+0x33/0x50 home/dubbo/net/mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 home/dubbo/net/mm/kasan/common.c:52
 ____kasan_kmalloc home/dubbo/net/mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xa2/0xb0 home/dubbo/net/mm/kasan/common.c:383
 kasan_kmalloc home/dubbo/net/./include/linux/kasan.h:198 [inline]
 __do_kmalloc_node home/dubbo/net/mm/slab_common.c:1007 [inline]
 __kmalloc+0x60/0x100 home/dubbo/net/mm/slab_common.c:1020
 kmalloc home/dubbo/net/./include/linux/slab.h:604 [inline]
 sk_prot_alloc+0x1a4/0x2a0 home/dubbo/net/net/core/sock.c:2075
 sk_alloc+0x36/0xb80 home/dubbo/net/net/core/sock.c:2128
 bt_sock_alloc+0x3b/0x3e0 home/dubbo/net/net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc home/dubbo/net/net/bluetooth/sco.c:495 [inline]
 sco_sock_create+0xe3/0x3b0 home/dubbo/net/net/bluetooth/sco.c:526
 bt_sock_create+0x180/0x340 home/dubbo/net/net/bluetooth/af_bluetooth.c:132
 __sock_create+0x328/0x800 home/dubbo/net/net/socket.c:1569
 sock_create home/dubbo/net/net/socket.c:1620 [inline]
 __sys_socket_create home/dubbo/net/net/socket.c:1657 [inline]
 __sys_socket+0x14c/0x260 home/dubbo/net/net/socket.c:1704
 __do_sys_socket home/dubbo/net/net/socket.c:1718 [inline]
 __se_sys_socket home/dubbo/net/net/socket.c:1716 [inline]
 __x64_sys_socket+0x72/0xb0 home/dubbo/net/net/socket.c:1716
 do_syscall_x64 home/dubbo/net/arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x3f/0x110 home/dubbo/net/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
Freed by task 8209:
 kasan_save_stack+0x33/0x50 home/dubbo/net/mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 home/dubbo/net/mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 home/dubbo/net/mm/kasan/generic.c:522
 ____kasan_slab_free home/dubbo/net/mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x15b/0x1b0 home/dubbo/net/mm/kasan/common.c:200
 kasan_slab_free home/dubbo/net/./include/linux/kasan.h:164 [inline]
 slab_free_hook home/dubbo/net/mm/slub.c:1800 [inline]
 slab_free_freelist_hook+0x114/0x1e0 home/dubbo/net/mm/slub.c:1826
 slab_free home/dubbo/net/mm/slub.c:3809 [inline]
 __kmem_cache_free+0xc0/0x180 home/dubbo/net/mm/slub.c:3822
 sk_prot_free home/dubbo/net/net/core/sock.c:2111 [inline]
 __sk_destruct+0x602/0x770 home/dubbo/net/net/core/sock.c:2203
 sk_destruct+0xc2/0xf0 home/dubbo/net/net/core/sock.c:2218
 __sk_free+0xf4/0x3e0 home/dubbo/net/net/core/sock.c:2229
 sk_free+0x7c/0xa0 home/dubbo/net/net/core/sock.c:2240
 sock_put home/dubbo/net/./include/net/sock.h:1990 [inline]
 sco_sock_kill home/dubbo/net/net/bluetooth/sco.c:426 [inline]
 sco_sock_kill+0x19d/0x1c0 home/dubbo/net/net/bluetooth/sco.c:416
 sco_sock_release+0x154/0x2c0 home/dubbo/net/net/bluetooth/sco.c:1256
 __sock_release+0xae/0x260 home/dubbo/net/net/socket.c:659
 sock_close+0x1c/0x20 home/dubbo/net/net/socket.c:1419
 __fput+0x270/0xbb0 home/dubbo/net/fs/file_table.c:394
 task_work_run+0x14d/0x240 home/dubbo/net/kernel/task_work.c:180
 get_signal+0x1077/0x26e0 home/dubbo/net/kernel/signal.c:2680
 arch_do_signal_or_restart+0x90/0x7f0
home/dubbo/net/arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop home/dubbo/net/kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 home/dubbo/net/kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work
home/dubbo/net/kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x60 home/dubbo/net/kernel/entry/common.c:296
 do_syscall_64+0x4b/0x110 home/dubbo/net/arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
Last potentially related work creation:
 kasan_save_stack+0x33/0x50 home/dubbo/net/mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 home/dubbo/net/mm/kasan/generic.c:492
 __call_rcu_common.constprop.0+0x9a/0x790 home/dubbo/net/kernel/rcu/tree.c:2681
 netlink_release+0x120d/0x1ff0 home/dubbo/net/net/netlink/af_netlink.c:831
 __sock_release+0xae/0x260 home/dubbo/net/net/socket.c:659
 sock_close+0x1c/0x20 home/dubbo/net/net/socket.c:1419
 __fput+0x270/0xbb0 home/dubbo/net/fs/file_table.c:394
 __fput_sync+0x47/0x50 home/dubbo/net/fs/file_table.c:475
 __do_sys_close home/dubbo/net/fs/open.c:1590 [inline]
 __se_sys_close home/dubbo/net/fs/open.c:1575 [inline]
 __x64_sys_close+0x87/0xf0 home/dubbo/net/fs/open.c:1575
 do_syscall_x64 home/dubbo/net/arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x3f/0x110 home/dubbo/net/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
The buggy address belongs to the object at ffff888156922000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff888156922000, ffff888156922800)
The buggy address belongs to the physical page:
page:ffffea00055a4800 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x15690
head:ffffea00055a4800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000840(slab|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 057ff00000000840 ffff888012c43240 ffffea00053b0e10 ffffea000502e810
raw: 0000000000000000 0000000000050005 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask
0xd2040(__GFP_IO|__GFP_N3
 set_page_owner home/dubbo/net/./include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2cf/0x340 home/dubbo/net/mm/page_alloc.c:1537
 prep_new_page home/dubbo/net/mm/page_alloc.c:1544 [inline]
 get_page_from_freelist+0xa28/0x36c0 home/dubbo/net/mm/page_alloc.c:3312
 __alloc_pages+0x1d0/0x4a0 home/dubbo/net/mm/page_alloc.c:4568
 alloc_pages_mpol+0x258/0x5f0 home/dubbo/net/mm/mempolicy.c:2133
 alloc_slab_page home/dubbo/net/mm/slub.c:1870 [inline]
 allocate_slab+0x251/0x380 home/dubbo/net/mm/slub.c:2017
 new_slab home/dubbo/net/mm/slub.c:2070 [inline]
 ___slab_alloc+0x8c7/0x1580 home/dubbo/net/mm/slub.c:3223
 __slab_alloc.constprop.0+0x56/0xa0 home/dubbo/net/mm/slub.c:3322
 __slab_alloc_node home/dubbo/net/mm/slub.c:3375 [inline]
 slab_alloc_node home/dubbo/net/mm/slub.c:3468 [inline]
 __kmem_cache_alloc_node+0x131/0x310 home/dubbo/net/mm/slub.c:3517
 __do_kmalloc_node home/dubbo/net/mm/slab_common.c:1006 [inline]
 __kmalloc+0x4f/0x100 home/dubbo/net/mm/slab_common.c:1020
 kmalloc home/dubbo/net/./include/linux/slab.h:604 [inline]
 kzalloc home/dubbo/net/./include/linux/slab.h:721 [inline]
 tomoyo_init_log+0x1276/0x1f60 home/dubbo/net/security/tomoyo/audit.c:275
 tomoyo_supervisor+0x30c/0x1170 home/dubbo/net/security/tomoyo/common.c:2089
 tomoyo_audit_env_log home/dubbo/net/security/tomoyo/environ.c:36 [inline]
 tomoyo_env_perm+0x18f/0x200 home/dubbo/net/security/tomoyo/environ.c:63
 tomoyo_environ home/dubbo/net/security/tomoyo/domain.c:672 [inline]
 tomoyo_find_next_domain+0xed8/0x2020
home/dubbo/net/security/tomoyo/domain.c:878
 tomoyo_bprm_check_security home/dubbo/net/security/tomoyo/tomoyo.c:101 [inline]
 tomoyo_bprm_check_security+0x12b/0x1d0
home/dubbo/net/security/tomoyo/tomoyo.c:91
 security_bprm_check+0x6a/0xe0 home/dubbo/net/security/security.c:1103
 search_binary_handler home/dubbo/net/fs/exec.c:1725 [inline]
 exec_binprm home/dubbo/net/fs/exec.c:1779 [inline]
 bprm_execve home/dubbo/net/fs/exec.c:1854 [inline]
 bprm_execve+0x73a/0x1a90 home/dubbo/net/fs/exec.c:1810
page last free stack trace:
 reset_page_owner home/dubbo/net/./include/linux/page_owner.h:24 [inline]
 free_pages_prepare home/dubbo/net/mm/page_alloc.c:1137 [inline]
 free_unref_page_prepare+0x4e5/0xa20 home/dubbo/net/mm/page_alloc.c:2347
 free_unref_page+0x33/0x3b0 home/dubbo/net/mm/page_alloc.c:2487
 qlink_free home/dubbo/net/mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 home/dubbo/net/mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x18e/0x1d0 home/dubbo/net/mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x65/0x90 home/dubbo/net/mm/kasan/common.c:305
 kasan_slab_alloc home/dubbo/net/./include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook home/dubbo/net/mm/slab.h:763 [inline]
 slab_alloc_node home/dubbo/net/mm/slub.c:3478 [inline]
 slab_alloc home/dubbo/net/mm/slub.c:3486 [inline]
 __kmem_cache_alloc_lru home/dubbo/net/mm/slub.c:3493 [inline]
 kmem_cache_alloc+0x163/0x390 home/dubbo/net/mm/slub.c:3502
 kmem_cache_zalloc home/dubbo/net/./include/linux/slab.h:711 [inline]
 alloc_empty_file+0x73/0x1d0 home/dubbo/net/fs/file_table.c:216
 path_openat+0xdd/0x2c40 home/dubbo/net/fs/namei.c:3765
 do_filp_open+0x1de/0x430 home/dubbo/net/fs/namei.c:3809
 do_sys_openat2+0x176/0x1e0 home/dubbo/net/fs/open.c:1440
 do_sys_open home/dubbo/net/fs/open.c:1455 [inline]
 __do_sys_openat home/dubbo/net/fs/open.c:1471 [inline]
 __se_sys_openat home/dubbo/net/fs/open.c:1466 [inline]
 __x64_sys_openat+0x175/0x210 home/dubbo/net/fs/open.c:1466
 do_syscall_x64 home/dubbo/net/arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x3f/0x110 home/dubbo/net/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
Memory state around the buggy address:
 ffff888156921f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888156922000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888156922080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888156922100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888156922180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


and my reproducer is at the same kernel commit at the lastest net tree
kernel commit: 1ae4cd3cbdd08287c56c4cc816ebf05eb6681a0f
kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=b50bd31249191be8

KASAN: slab-out-of-bounds Write in sco_sock_timeout:
https://gist.github.com/xrivendell7/0dbaa3529a9845b008c31e0bc6c29236
KASAN: slab-use-after-free Write in sco_conn_del:
https://gist.github.com/xrivendell7/b813252b1c8f3f35aaee1af60b698d0a
KASAN: wild-memory-access Read in lock_sock_nested:
https://gist.github.com/xrivendell7/f2a0fba9a55413c64c6153d03cd3df58

all the gist contains the report, repro.c and repro.txt
BTW, I also run another crash maybe related to this one, Titled:

KASAN: use-after-free Write in sco_sock_timeout
KASAN: slab-out-of-bounds Write in sco_sock_timeout
KASAN: slab-use-after-free Write in __sco_sock_close
WARNING: refcount bug in sco_sock_timeout
INFO: trying to register non-static key in sco_sock_timeout

However, for now, i can not reproduce those bugs with stable reproducer.
I hope is helps.

Best Regards
xingwei Lee

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
Write of size 4 at addr ffff888022136080 by task kworker/1:0/25

CPU: 1 UID: 0 PID: 25 Comm: kworker/1:0 Not tainted 6.12.0-rc1-syzkaller-ge32cde8d2bd7-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 4550:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x255/0x500 security/tomoyo/file.c:771
 security_file_open+0x777/0x990 security/security.c:3107
 do_dentry_open+0x369/0x1460 fs/open.c:945
 vfs_open+0x3e/0x330 fs/open.c:1088
 do_open fs/namei.c:3774 [inline]
 path_openat+0x2c84/0x3590 fs/namei.c:3933
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 4550:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 tomoyo_realpath_from_path+0x5a9/0x5e0 security/tomoyo/realpath.c:286
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x255/0x500 security/tomoyo/file.c:771
 security_file_open+0x777/0x990 security/security.c:3107
 do_dentry_open+0x369/0x1460 fs/open.c:945
 vfs_open+0x3e/0x330 fs/open.c:1088
 do_open fs/namei.c:3774 [inline]
 path_openat+0x2c84/0x3590 fs/namei.c:3933
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888022136000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 128 bytes inside of
 freed 4096-byte region [ffff888022136000, ffff888022137000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22130
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0000884c01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4550, tgid 4550 (udevd), ts 121918980453, free_ts 121043303487
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 kernfs_iop_get_link+0x67/0x5a0 fs/kernfs/symlink.c:135
 vfs_readlink+0x170/0x3b0 fs/namei.c:5267
 do_readlinkat+0x249/0x3a0 fs/stat.c:551
 __do_sys_readlink fs/stat.c:574 [inline]
 __se_sys_readlink fs/stat.c:571 [inline]
 __x64_sys_readlink+0x7f/0x90 fs/stat.c:571
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 54 tgid 54 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 __slab_free+0x31b/0x3d0 mm/slub.c:4491
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4086 [inline]
 slab_alloc_node mm/slub.c:4135 [inline]
 __kmalloc_cache_noprof+0x132/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 hci_cmd_sync_submit+0xcb/0x2f0 net/bluetooth/hci_sync.c:710
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff888022135f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888022136000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888022136080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888022136100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888022136180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         e32cde8d Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14e62580580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5997f8b13c390e73
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12698927980000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_conn_del

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_conn_del+0xa5/0x310 net/bluetooth/sco.c:199
Write of size 4 at addr ffff88802ad8c080 by task kworker/u9:2/5106

CPU: 0 UID: 0 PID: 5106 Comm: kworker/u9:2 Not tainted 6.12.0-rc1-syzkaller-ge32cde8d2bd7-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_conn_del+0xa5/0x310 net/bluetooth/sco.c:199
 sco_connect_cfm+0xe6/0xb40 net/bluetooth/sco.c:1363
 hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline]
 hci_conn_failed+0x1d0/0x300 net/bluetooth/hci_conn.c:1262
 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5586
 hci_cmd_sync_work+0x22d/0x400 net/bluetooth/hci_sync.c:328
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5633:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:499 [inline]
 sco_sock_create+0xbb/0x390 net/bluetooth/sco.c:530
 bt_sock_create+0x163/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5634:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 sk_prot_free net/core/sock.c:2200 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2292
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1258
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802ad8c000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff88802ad8c000, ffff88802ad8c800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2ad88
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442000 0000000000000000 0000000000000001
raw: 0000000000000000 0000000080080008 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442000 0000000000000000 0000000000000001
head: 0000000000000000 0000000080080008 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0000ab6201 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4761, tgid 4761 (dhcpcd), ts 68514784369, free_ts 68293337708
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 rtnl_newlink+0xf2/0x20a0 net/core/rtnetlink.c:3739
 rtnetlink_rcv_msg+0x741/0xcf0 net/core/rtnetlink.c:6646
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7f8/0x990 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:744
 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2602
page last free pid 5174 tgid 5174 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 discard_slab mm/slub.c:2678 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3146
 put_cpu_partial+0x17c/0x250 mm/slub.c:3221
 __slab_free+0x2ea/0x3d0 mm/slub.c:4450
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4086 [inline]
 slab_alloc_node mm/slub.c:4135 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142
 vm_area_alloc+0x24/0x1d0 kernel/fork.c:472
 mmap_region+0x1132/0x2990 mm/mmap.c:1424
 do_mmap+0x8f0/0x1000 mm/mmap.c:496
 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:588
 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802ad8bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802ad8c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802ad8c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88802ad8c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802ad8c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         e32cde8d Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13bb23d0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5997f8b13c390e73
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14ebd39f980000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
Write of size 4 at addr ffff88807e2d5080 by task kworker/1:1/47

CPU: 1 UID: 0 PID: 47 Comm: kworker/1:1 Not tainted 6.12.0-rc1-syzkaller-ge32cde8d2bd7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5759:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:500 [inline]
 sco_sock_create+0xbb/0x390 net/bluetooth/sco.c:531
 bt_sock_create+0x163/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5760:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 sk_prot_free net/core/sock.c:2200 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2292
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1259
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807e2d5000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff88807e2d5000, ffff88807e2d5800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e2d0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442000 ffffea0000a07800 dead000000000002
raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442000 ffffea0000a07800 dead000000000002
head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0001f8b401 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4533, tgid 4533 (acpid), ts 19751533769, free_ts 17515017965
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x25a/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 __netlink_create+0x65/0x260 net/netlink/af_netlink.c:646
 netlink_create+0x3ab/0x560 net/netlink/af_netlink.c:704
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 free_contig_range+0x152/0x550 mm/page_alloc.c:6748
 destroy_args+0x8a/0x840 mm/debug_vm_pgtable.c:1017
 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1397
 do_one_initcall+0x24a/0x880 init/main.c:1269
 do_initcall_level+0x157/0x210 init/main.c:1331
 do_initcalls+0x3f/0x80 init/main.c:1347
 kernel_init_freeable+0x435/0x5d0 init/main.c:1580
 kernel_init+0x1d/0x2b0 init/main.c:1469
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff88807e2d4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807e2d5000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807e2d5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88807e2d5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807e2d5180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         e32cde8d Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=174f23d0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5997f8b13c390e73
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
Write of size 4 at addr ffff8881436fb080 by task kworker/0:3/1150

CPU: 0 UID: 0 PID: 1150 Comm: kworker/0:3 Not tainted 6.12.0-rc1-syzkaller-ge32cde8d2bd7-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5769:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:489 [inline]
 sco_sock_create+0xbb/0x390 net/bluetooth/sco.c:520
 bt_sock_create+0x163/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5770:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 sk_prot_free net/core/sock.c:2200 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2292
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1248
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8881436fb000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff8881436fb000, ffff8881436fb800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1436f8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff888015442000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 057ff00000000040 ffff888015442000 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 057ff00000000003 ffffea00050dbe01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2322085089, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 acpi_add_single_object+0xe5/0x1e00 drivers/acpi/scan.c:1876
 acpi_bus_check_add+0x32b/0x980 drivers/acpi/scan.c:2181
 acpi_ns_walk_namespace+0x296/0x4f0
 acpi_walk_namespace+0xeb/0x130 drivers/acpi/acpica/nsxfeval.c:606
 acpi_bus_scan+0x4c1/0x560 drivers/acpi/scan.c:2595
 acpi_scan_init+0x267/0x730 drivers/acpi/scan.c:2747
 acpi_init+0x159/0x240 drivers/acpi/bus.c:1466
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881436faf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881436fb000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881436fb080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8881436fb100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881436fb180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         e32cde8d Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13299927980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5997f8b13c390e73
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=121f23d0580000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
Write of size 4 at addr ffff8881442d6080 by task kworker/1:3/5112

CPU: 1 UID: 0 PID: 5112 Comm: kworker/1:3 Not tainted 6.12.0-rc1-syzkaller-gf23aa4c0761a-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5785:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:490 [inline]
 sco_sock_create+0xbb/0x390 net/bluetooth/sco.c:521
 bt_sock_create+0x163/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5786:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 sk_prot_free net/core/sock.c:2200 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2292
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1249
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8881442d6000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff8881442d6000, ffff8881442d6800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1442d0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff888015442000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 057ff00000000040 ffff888015442000 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 057ff00000000003 ffffea000510b401 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2464151042, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 acpi_ds_create_walk_state+0x103/0x2a0 drivers/acpi/acpica/dswstate.c:518
 acpi_ps_execute_method+0x245/0x880 drivers/acpi/acpica/psxface.c:134
 acpi_ns_evaluate+0x5df/0xa40 drivers/acpi/acpica/nseval.c:205
 acpi_evaluate_object+0x59b/0xaf0 drivers/acpi/acpica/nsxfeval.c:354
 map_mat_entry drivers/acpi/processor_core.c:241 [inline]
 acpi_get_phys_id+0xa5/0xd00 drivers/acpi/processor_core.c:274
 acpi_get_cpuid+0x28/0x1f0 drivers/acpi/processor_core.c:332
 processor_physically_present+0x29a/0x380 drivers/acpi/acpi_processor.c:565
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881442d5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881442d6000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881442d6080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8881442d6100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881442d6180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         f23aa4c0 Merge tag 'hid-for-linus-2024090201' of git:/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12d02307980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14559927980000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in hci_conn_drop

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x280 include/net/bluetooth/hci_core.h:1548
Write of size 4 at addr ffff88801ea58010 by task syz-executor.0/5537

CPU: 0 UID: 0 PID: 5537 Comm: syz-executor.0 Not tainted 6.12.0-rc1-syzkaller-g7ec462100ef9-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
 hci_conn_drop+0x34/0x280 include/net/bluetooth/hci_core.h:1548
 sco_conn_destruct+0x57/0x100 net/bluetooth/sco.c:166
 sco_sock_destruct+0x43/0x90 net/bluetooth/sco.c:407
 __sk_destruct+0x5a/0x5f0 net/core/sock.c:2259
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1259
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 __do_sys_close fs/open.c:1565 [inline]
 __se_sys_close fs/open.c:1550 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1550
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa71cc7cd5a
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24
RSP: 002b:00007ffc91af2860 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007fa71cc7cd5a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007fa71cdad980 R08: 0000001b2d160000 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000016f8e
R13: ffffffffffffffff R14: 00007fa71c800000 R15: 0000000000016c4d
 </TASK>

Allocated by task 5455:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4296
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 __hci_conn_add+0x2f9/0x1850 net/bluetooth/hci_conn.c:932
 hci_conn_add_unset net/bluetooth/hci_conn.c:1041 [inline]
 hci_connect_sco+0xd0/0x370 net/bluetooth/hci_conn.c:1689
 sco_connect net/bluetooth/sco.c:279 [inline]
 sco_sock_connect+0x2fc/0x990 net/bluetooth/sco.c:596
 __sys_connect_file net/socket.c:2066 [inline]
 __sys_connect+0x2d3/0x300 net/socket.c:2083
 __do_sys_connect net/socket.c:2093 [inline]
 __se_sys_connect net/socket.c:2090 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2090
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 4494:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 device_release+0x9b/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x231/0x480 lib/kobject.c:737
 hci_conn_cleanup net/bluetooth/hci_conn.c:174 [inline]
 hci_conn_del+0x8c4/0xc40 net/bluetooth/hci_conn.c:1160
 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5586
 hci_cmd_sync_work+0x22d/0x400 net/bluetooth/hci_sync.c:328
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339
 queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2552
 sco_conn_destruct+0x57/0x100 net/bluetooth/sco.c:166
 sco_sock_destruct+0x43/0x90 net/bluetooth/sco.c:407
 __sk_destruct+0x5a/0x5f0 net/core/sock.c:2259
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1259
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801ea58000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 16 bytes inside of
 freed 8192-byte region [ffff88801ea58000, ffff88801ea5a000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ea58
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442280 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442280 0000000000000000 dead000000000001
head: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea00007a9601 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4772, tgid 4772 (dhcpcd-run-hook), ts 33884825404, free_ts 32631813811
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
 tomoyo_init_log+0x11cd/0x2050 security/tomoyo/audit.c:264
 tomoyo_supervisor+0x38a/0x11f0 security/tomoyo/common.c:2099
 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
 tomoyo_env_perm+0x178/0x210 security/tomoyo/environ.c:63
 tomoyo_environ security/tomoyo/domain.c:672 [inline]
 tomoyo_find_next_domain+0x146e/0x1d40 security/tomoyo/domain.c:881
 tomoyo_bprm_check_security+0x114/0x180 security/tomoyo/hooks.h:76
 security_bprm_check+0x86/0x250 security/security.c:1296
 search_binary_handler fs/exec.c:1740 [inline]
 exec_binprm fs/exec.c:1794 [inline]
 bprm_execve+0xa56/0x1770 fs/exec.c:1845
page last free pid 4743 tgid 4743 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 discard_slab mm/slub.c:2678 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3146
 put_cpu_partial+0x17c/0x250 mm/slub.c:3221
 __slab_free+0x2ea/0x3d0 mm/slub.c:4450
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4086 [inline]
 slab_alloc_node mm/slub.c:4135 [inline]
 __kmalloc_cache_noprof+0x132/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 tomoyo_print_header security/tomoyo/audit.c:156 [inline]
 tomoyo_init_log+0x1ca/0x2050 security/tomoyo/audit.c:255
 tomoyo_supervisor+0x38a/0x11f0 security/tomoyo/common.c:2099
 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
 tomoyo_path_permission+0x243/0x360 security/tomoyo/file.c:587
 tomoyo_path_perm+0x480/0x740 security/tomoyo/file.c:838
 security_inode_getattr+0x130/0x330 security/security.c:2371
 vfs_getattr+0x45/0x430 fs/stat.c:204
 vfs_fstat fs/stat.c:229 [inline]
 vfs_fstatat+0xe4/0x190 fs/stat.c:338
 __do_sys_newfstatat fs/stat.c:505 [inline]
 __se_sys_newfstatat fs/stat.c:499 [inline]
 __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499

Memory state around the buggy address:
 ffff88801ea57f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801ea57f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801ea58000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff88801ea58080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801ea58100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         7ec46210 Merge tag 'pull-work.unaligned' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=114d5527980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15355527980000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_destruct

==================================================================
BUG: KASAN: slab-use-after-free in sco_conn_destruct net/bluetooth/sco.c:167 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_destruct+0xb9/0x170 net/bluetooth/sco.c:409
Write of size 8 at addr ffff88807926cfe8 by task syz-executor.0/5580

CPU: 0 UID: 0 PID: 5580 Comm: syz-executor.0 Not tainted 6.12.0-rc1-syzkaller-g7ec462100ef9-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 sco_conn_destruct net/bluetooth/sco.c:167 [inline]
 sco_sock_destruct+0xb9/0x170 net/bluetooth/sco.c:409
 __sk_destruct+0x5a/0x5f0 net/core/sock.c:2259
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1261
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f16c9a7de69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f16ca8910c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: fffffffffffffffc RBX: 00007f16c9babf80 RCX: 00007f16c9a7de69
RDX: 0000000000000008 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 00007f16c9aca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f16c9babf80 R15: 00007ffceef62378
 </TASK>

Allocated by task 5580:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4296
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 __hci_conn_add+0x2f9/0x1850 net/bluetooth/hci_conn.c:932
 hci_conn_add_unset net/bluetooth/hci_conn.c:1041 [inline]
 hci_connect_sco+0xd0/0x370 net/bluetooth/hci_conn.c:1689
 sco_connect net/bluetooth/sco.c:281 [inline]
 sco_sock_connect+0x2fc/0x990 net/bluetooth/sco.c:598
 __sys_connect_file net/socket.c:2066 [inline]
 __sys_connect+0x2d3/0x300 net/socket.c:2083
 __do_sys_connect net/socket.c:2093 [inline]
 __se_sys_connect net/socket.c:2090 [inline]
 __x64_sys_connect+0x7a/0x90 net/socket.c:2090
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 54:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 device_release+0x9b/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x231/0x480 lib/kobject.c:737
 hci_conn_cleanup net/bluetooth/hci_conn.c:174 [inline]
 hci_conn_del+0x8c4/0xc40 net/bluetooth/hci_conn.c:1160
 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5586
 hci_cmd_sync_work+0x22d/0x400 net/bluetooth/hci_sync.c:328
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:541
 insert_work+0x3e/0x330 kernel/workqueue.c:2183
 __queue_work+0xc8b/0xf50 kernel/workqueue.c:2339
 queue_delayed_work_on+0x1ca/0x390 kernel/workqueue.c:2552
 sco_chan_del net/bluetooth/sco.c:190 [inline]
 __sco_sock_close+0x22b/0x430 net/bluetooth/sco.c:461
 sco_sock_close net/bluetooth/sco.c:476 [inline]
 sco_sock_release+0xb3/0x320 net/bluetooth/sco.c:1251
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807926c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 4072 bytes inside of
 freed 8192-byte region [ffff88807926c000, ffff88807926e000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x79268
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442280 0000000000000000 0000000000000001
raw: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442280 0000000000000000 0000000000000001
head: 0000000000000000 0000000080020002 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0001e49a01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4757, tgid 4757 (start-stop-daem), ts 32264510159, free_ts 32243341192
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4291
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
 tomoyo_init_log+0x11cd/0x2050 security/tomoyo/audit.c:264
 tomoyo_supervisor+0x38a/0x11f0 security/tomoyo/common.c:2099
 tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
 tomoyo_env_perm+0x178/0x210 security/tomoyo/environ.c:63
 tomoyo_environ security/tomoyo/domain.c:672 [inline]
 tomoyo_find_next_domain+0x146e/0x1d40 security/tomoyo/domain.c:881
 tomoyo_bprm_check_security+0x114/0x180 security/tomoyo/hooks.h:76
 security_bprm_check+0x86/0x250 security/security.c:1296
 search_binary_handler fs/exec.c:1740 [inline]
 exec_binprm fs/exec.c:1794 [inline]
 bprm_execve+0xa56/0x1770 fs/exec.c:1845
page last free pid 4757 tgid 4757 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 discard_slab mm/slub.c:2678 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3146
 put_cpu_partial+0x17c/0x250 mm/slub.c:3221
 __slab_free+0x2ea/0x3d0 mm/slub.c:4450
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4086 [inline]
 slab_alloc_node mm/slub.c:4135 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1a6/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 load_elf_phdrs fs/binfmt_elf.c:526 [inline]
 load_elf_binary+0x2eb/0x2710 fs/binfmt_elf.c:855
 search_binary_handler fs/exec.c:1752 [inline]
 exec_binprm fs/exec.c:1794 [inline]
 bprm_execve+0xafa/0x1770 fs/exec.c:1845
 do_execveat_common+0x55f/0x6f0 fs/exec.c:1952
 do_execve fs/exec.c:2026 [inline]
 __do_sys_execve fs/exec.c:2102 [inline]
 __se_sys_execve fs/exec.c:2097 [inline]
 __x64_sys_execve+0x92/0xb0 fs/exec.c:2097
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807926ce80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807926cf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807926cf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff88807926d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807926d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         7ec46210 Merge tag 'pull-work.unaligned' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13e97580580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11f17580580000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
Write of size 4 at addr ffff88802639a080 by task kworker/1:2/1808

CPU: 1 UID: 0 PID: 1808 Comm: kworker/1:2 Not tainted 6.12.0-rc1-syzkaller-00113-g8c245fe7dde3-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 25:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4284
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1322 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x254/0xaa0 drivers/net/netdevsim/dev.c:850
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 25:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 skb_kfree_head net/core/skbuff.c:1086 [inline]
 skb_free_head net/core/skbuff.c:1098 [inline]
 skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1190 [inline]
 __kfree_skb net/core/skbuff.c:1204 [inline]
 consume_skb+0x9f/0xf0 net/core/skbuff.c:1436
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
 nsim_dev_trap_report_work+0x765/0xaa0 drivers/net/netdevsim/dev.c:850
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88802639a000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 128 bytes inside of
 freed 4096-byte region [ffff88802639a000, ffff88802639b000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26398
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea000098e601 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5398, tgid 5398 (udevd), ts 123333990998, free_ts 123322335448
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x25a/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path2_perm+0x3eb/0xbb0 security/tomoyo/file.c:923
 tomoyo_path_rename+0x198/0x1e0 security/tomoyo/hooks.h:274
 security_path_rename+0x266/0x4e0 security/security.c:2020
 do_renameat2+0x94a/0x13f0 fs/namei.c:5157
 __do_sys_rename fs/namei.c:5217 [inline]
 __se_sys_rename fs/namei.c:5215 [inline]
 __x64_sys_rename+0x82/0x90 fs/namei.c:5215
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 4548 tgid 4548 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 __slab_free+0x31b/0x3d0 mm/slub.c:4491
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4086 [inline]
 slab_alloc_node mm/slub.c:4135 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1a6/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822
 security_inode_getattr+0x130/0x330 security/security.c:2371
 vfs_getattr+0x45/0x430 fs/stat.c:204
 vfs_fstat fs/stat.c:229 [inline]
 vfs_fstatat+0xe4/0x190 fs/stat.c:338
 __do_sys_newfstatat fs/stat.c:505 [inline]
 __se_sys_newfstatat fs/stat.c:499 [inline]
 __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888026399f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802639a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802639a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88802639a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802639a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         8c245fe7 Merge tag 'net-6.12-rc2' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13156307980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17377580580000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[Luiz Augusto von Dentz]

On Thu, Oct 3, 2024 at 3:44 PM syzbot
<syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> KASAN: slab-use-after-free Write in sco_sock_timeout
>
> ==================================================================
> BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
> BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
> BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
> BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
> BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
> BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
> BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
> Write of size 4 at addr ffff88802639a080 by task kworker/1:2/1808

This really doesn't make much sense, it seems this is catching a UAF
on sock_hold but the backtrace shows it was freed with skb_free, even
if the memory was reclaimed and then reallocated that would just it
more difficult to find out why this is happening.

> CPU: 1 UID: 0 PID: 1808 Comm: kworker/1:2 Not tainted 6.12.0-rc1-syzkaller-00113-g8c245fe7dde3-dirty #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> Workqueue: events sco_sock_timeout
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:94 [inline]
>  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
>  print_address_description mm/kasan/report.c:377 [inline]
>  print_report+0x169/0x550 mm/kasan/report.c:488
>  kasan_report+0x143/0x180 mm/kasan/report.c:601
>  kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
>  instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
>  atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
>  __refcount_add include/linux/refcount.h:184 [inline]
>  __refcount_inc include/linux/refcount.h:241 [inline]
>  refcount_inc include/linux/refcount.h:258 [inline]
>  sock_hold include/net/sock.h:781 [inline]
>  sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
>  process_one_work kernel/workqueue.c:3229 [inline]
>  process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
>  worker_thread+0x870/0xd30 kernel/workqueue.c:3391
>  kthread+0x2f2/0x390 kernel/kthread.c:389
>  ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>  </TASK>
>
> Allocated by task 25:
>  kasan_save_stack mm/kasan/common.c:47 [inline]
>  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
>  poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
>  __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
>  kasan_kmalloc include/linux/kasan.h:257 [inline]
>  __do_kmalloc_node mm/slub.c:4265 [inline]
>  __kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4284
>  kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
>  __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
>  alloc_skb include/linux/skbuff.h:1322 [inline]
>  nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
>  nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
>  nsim_dev_trap_report_work+0x254/0xaa0 drivers/net/netdevsim/dev.c:850
>  process_one_work kernel/workqueue.c:3229 [inline]
>  process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
>  worker_thread+0x870/0xd30 kernel/workqueue.c:3391
>  kthread+0x2f2/0x390 kernel/kthread.c:389
>  ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> Freed by task 25:
>  kasan_save_stack mm/kasan/common.c:47 [inline]
>  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
>  kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
>  poison_slab_object mm/kasan/common.c:247 [inline]
>  __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
>  kasan_slab_free include/linux/kasan.h:230 [inline]
>  slab_free_hook mm/slub.c:2343 [inline]
>  slab_free mm/slub.c:4580 [inline]
>  kfree+0x1a0/0x440 mm/slub.c:4728
>  skb_kfree_head net/core/skbuff.c:1086 [inline]
>  skb_free_head net/core/skbuff.c:1098 [inline]
>  skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125
>  skb_release_all net/core/skbuff.c:1190 [inline]
>  __kfree_skb net/core/skbuff.c:1204 [inline]
>  consume_skb+0x9f/0xf0 net/core/skbuff.c:1436
>  nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
>  nsim_dev_trap_report_work+0x765/0xaa0 drivers/net/netdevsim/dev.c:850
>  process_one_work kernel/workqueue.c:3229 [inline]
>  process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
>  worker_thread+0x870/0xd30 kernel/workqueue.c:3391
>  kthread+0x2f2/0x390 kernel/kthread.c:389
>  ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
>  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
>
> The buggy address belongs to the object at ffff88802639a000
>  which belongs to the cache kmalloc-4k of size 4096
> The buggy address is located 128 bytes inside of
>  freed 4096-byte region [ffff88802639a000, ffff88802639b000)
>
> The buggy address belongs to the physical page:
> page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26398
> head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
> flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
> page_type: f5(slab)
> raw: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
> raw: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
> head: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
> head: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
> head: 00fff00000000003 ffffea000098e601 ffffffffffffffff 0000000000000000
> head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
> page_owner tracks the page as allocated
> page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5398, tgid 5398 (udevd), ts 123333990998, free_ts 123322335448
>  set_page_owner include/linux/page_owner.h:32 [inline]
>  post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
>  prep_new_page mm/page_alloc.c:1545 [inline]
>  get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
>  __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
>  alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
>  alloc_slab_page+0x6a/0x120 mm/slub.c:2413
>  allocate_slab+0x5a/0x2f0 mm/slub.c:2579
>  new_slab mm/slub.c:2632 [inline]
>  ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
>  __slab_alloc+0x58/0xa0 mm/slub.c:3909
>  __slab_alloc_node mm/slub.c:3962 [inline]
>  slab_alloc_node mm/slub.c:4123 [inline]
>  __do_kmalloc_node mm/slub.c:4264 [inline]
>  __kmalloc_noprof+0x25a/0x400 mm/slub.c:4277
>  kmalloc_noprof include/linux/slab.h:882 [inline]
>  tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
>  tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
>  tomoyo_path2_perm+0x3eb/0xbb0 security/tomoyo/file.c:923
>  tomoyo_path_rename+0x198/0x1e0 security/tomoyo/hooks.h:274
>  security_path_rename+0x266/0x4e0 security/security.c:2020
>  do_renameat2+0x94a/0x13f0 fs/namei.c:5157
>  __do_sys_rename fs/namei.c:5217 [inline]
>  __se_sys_rename fs/namei.c:5215 [inline]
>  __x64_sys_rename+0x82/0x90 fs/namei.c:5215
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> page last free pid 4548 tgid 4548 stack trace:
>  reset_page_owner include/linux/page_owner.h:25 [inline]
>  free_pages_prepare mm/page_alloc.c:1108 [inline]
>  free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
>  __slab_free+0x31b/0x3d0 mm/slub.c:4491
>  qlink_free mm/kasan/quarantine.c:163 [inline]
>  qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
>  kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
>  __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
>  kasan_slab_alloc include/linux/kasan.h:247 [inline]
>  slab_post_alloc_hook mm/slub.c:4086 [inline]
>  slab_alloc_node mm/slub.c:4135 [inline]
>  __do_kmalloc_node mm/slub.c:4264 [inline]
>  __kmalloc_noprof+0x1a6/0x400 mm/slub.c:4277
>  kmalloc_noprof include/linux/slab.h:882 [inline]
>  tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
>  tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
>  tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822
>  security_inode_getattr+0x130/0x330 security/security.c:2371
>  vfs_getattr+0x45/0x430 fs/stat.c:204
>  vfs_fstat fs/stat.c:229 [inline]
>  vfs_fstatat+0xe4/0x190 fs/stat.c:338
>  __do_sys_newfstatat fs/stat.c:505 [inline]
>  __se_sys_newfstatat fs/stat.c:499 [inline]
>  __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> Memory state around the buggy address:
>  ffff888026399f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>  ffff88802639a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >ffff88802639a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                    ^
>  ffff88802639a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  ffff88802639a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> Tested on:
>
> commit:         8c245fe7 Merge tag 'net-6.12-rc2' of git://git.kernel...
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13156307980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e
> dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> patch:          https://syzkaller.appspot.com/x/patch.diff?x=17377580580000
>


-- 
Luiz Augusto von Dentz

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_conn_del

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_conn_del+0x9a/0x2c0 net/bluetooth/sco.c:227
Write of size 4 at addr ffff88801f485080 by task kworker/u9:1/4491

CPU: 0 UID: 0 PID: 4491 Comm: kworker/u9:1 Not tainted 6.12.0-rc1-syzkaller-00125-g0c559323bbaa-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_conn_del+0x9a/0x2c0 net/bluetooth/sco.c:227
 sco_connect_cfm+0xe6/0xb40 net/bluetooth/sco.c:1381
 hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline]
 hci_conn_failed+0x1d0/0x300 net/bluetooth/hci_conn.c:1262
 hci_abort_conn_sync+0x583/0xde0 net/bluetooth/hci_sync.c:5586
 hci_cmd_sync_work+0x22d/0x400 net/bluetooth/hci_sync.c:328
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5576:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:517 [inline]
 sco_sock_create+0xbb/0x390 net/bluetooth/sco.c:548
 bt_sock_create+0x163/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5577:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 sk_prot_free net/core/sock.c:2200 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2292
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1276
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801f485000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff88801f485000, ffff88801f485800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1f480
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442000 ffffea00007d4800 0000000000000002
raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442000 ffffea00007d4800 0000000000000002
head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea00007d2001 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5098, tgid 5098 (syz-executor.0), ts 63096504293, free_ts 61414295203
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x25a/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 kmalloc_array_noprof include/linux/slab.h:923 [inline]
 cache_create_net+0x83/0x270 net/sunrpc/cache.c:1743
 nfsd_idmap_init+0xe8/0x1e0 fs/nfsd/nfs4idmap.c:476
 nfsd_net_init+0x4b/0x450 fs/nfsd/nfsctl.c:2242
 ops_init+0x320/0x590 net/core/net_namespace.c:139
 setup_net+0x287/0x9e0 net/core/net_namespace.c:356
 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:494
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
page last free pid 5088 tgid 5085 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 discard_slab mm/slub.c:2678 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3146
 put_cpu_partial+0x17c/0x250 mm/slub.c:3221
 __slab_free+0x2ea/0x3d0 mm/slub.c:4450
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4086 [inline]
 slab_alloc_node mm/slub.c:4135 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1a6/0x400 mm/slub.c:4277
 kmalloc_noprof include/linux/slab.h:882 [inline]
 tomoyo_add_entry security/tomoyo/common.c:2033 [inline]
 tomoyo_supervisor+0xe0d/0x11f0 security/tomoyo/common.c:2105
 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
 tomoyo_path_permission+0x243/0x360 security/tomoyo/file.c:587
 tomoyo_path_perm+0x480/0x740 security/tomoyo/file.c:838
 security_inode_getattr+0x130/0x330 security/security.c:2371
 vfs_getattr+0x45/0x430 fs/stat.c:204
 vfs_statx_path fs/stat.c:251 [inline]
 vfs_statx+0x199/0x490 fs/stat.c:315
 vfs_fstatat+0x145/0x190 fs/stat.c:341
 __do_sys_newfstatat fs/stat.c:505 [inline]
 __se_sys_newfstatat fs/stat.c:499 [inline]
 __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499

Memory state around the buggy address:
 ffff88801f484f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801f485000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801f485080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88801f485100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801f485180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         0c559323 Merge tag 'rust-fixes-6.12' of https://github..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13fdb3d0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=160db3d0580000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
Write of size 4 at addr ffff88802719a080 by task kworker/1:3/5509

CPU: 1 UID: 0 PID: 5509 Comm: kworker/1:3 Not tainted 6.12.0-rc1-syzkaller-00125-g0c559323bbaa-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5115:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4265 [inline]
 __kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4284
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1322 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x254/0xaa0 drivers/net/netdevsim/dev.c:850
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 5115:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2343 [inline]
 slab_free mm/slub.c:4580 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4728
 skb_kfree_head net/core/skbuff.c:1086 [inline]
 skb_free_head net/core/skbuff.c:1098 [inline]
 skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1190 [inline]
 __kfree_skb net/core/skbuff.c:1204 [inline]
 consume_skb+0x9f/0xf0 net/core/skbuff.c:1436
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
 nsim_dev_trap_report_work+0x765/0xaa0 drivers/net/netdevsim/dev.c:850
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88802719a000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 128 bytes inside of
 freed 4096-byte region [ffff88802719a000, ffff88802719b000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27198
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff888015442140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea00009c6601 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5115, tgid 5115 (kworker/0:4), ts 122322399972, free_ts 122095257880
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2413
 allocate_slab+0x5a/0x2f0 mm/slub.c:2579
 new_slab mm/slub.c:2632 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3819
 __slab_alloc+0x58/0xa0 mm/slub.c:3909
 __slab_alloc_node mm/slub.c:3962 [inline]
 slab_alloc_node mm/slub.c:4123 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4284
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1322 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x254/0xaa0 drivers/net/netdevsim/dev.c:850
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
page last free pid 5425 tgid 5425 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 __slab_free+0x31b/0x3d0 mm/slub.c:4491
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4086 [inline]
 slab_alloc_node mm/slub.c:4135 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4142
 getname_flags+0xb7/0x540 fs/namei.c:139
 do_sys_openat2+0xd2/0x1d0 fs/open.c:1409
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_openat fs/open.c:1446 [inline]
 __se_sys_openat fs/open.c:1441 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888027199f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802719a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802719a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88802719a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802719a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         0c559323 Merge tag 'rust-fixes-6.12' of https://github..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=152e9307980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d0ca089c3fc6b54e
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12d69307980000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
Write of size 4 at addr ffff8880237b3080 by task kworker/0:1/9

CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.12.0-rc2-syzkaller-g8cf0b93919e1-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0x8b/0x270 net/bluetooth/sco.c:92
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5742:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:521 [inline]
 sco_sock_create+0xbb/0x390 net/bluetooth/sco.c:552
 bt_sock_create+0x163/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5743:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4727
 sk_prot_free net/core/sock.c:2200 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2292
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1280
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880237b3000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff8880237b3000, ffff8880237b3800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880237b5000 pfn:0x237b0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000240 ffff888015442000 ffffea00008c6a10 ffffea0001f13610
raw: ffff8880237b5000 0000000000080005 00000001f5000000 0000000000000000
head: 00fff00000000240 ffff888015442000 ffffea00008c6a10 ffffea0001f13610
head: ffff8880237b5000 0000000000080005 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea00008dec01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4550, tgid 4550 (udevd), ts 62011136939, free_ts 61932137647
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 __do_kmalloc_node mm/slub.c:4263 [inline]
 __kmalloc_noprof+0x25a/0x400 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 __netlink_create+0x65/0x260 net/netlink/af_netlink.c:646
 netlink_create+0x3ab/0x560 net/netlink/af_netlink.c:704
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
page last free pid 4539 tgid 4539 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 discard_slab mm/slub.c:2677 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3145
 put_cpu_partial+0x17c/0x250 mm/slub.c:3220
 __slab_free+0x2ea/0x3d0 mm/slub.c:4449
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4186
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1322 [inline]
 alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6612
 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2883
 unix_dgram_sendmsg+0x6d3/0x1f80 net/unix/af_unix.c:2027
 sock_sendmsg_nosec net/socket.c:729 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:744
 __sys_sendto+0x39b/0x4f0 net/socket.c:2209
 __do_sys_sendto net/socket.c:2221 [inline]
 __se_sys_sendto net/socket.c:2217 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2217
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83

Memory state around the buggy address:
 ffff8880237b2f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880237b3000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880237b3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880237b3100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880237b3180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         8cf0b939 Linux 6.12-rc2
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11e7db80580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a5119ec8290b5433
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=150b2707980000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0xa2/0x2d0 net/bluetooth/sco.c:140
Write of size 4 at addr ffff888140eac080 by task kworker/0:2/921

CPU: 0 UID: 0 PID: 921 Comm: kworker/0:2 Not tainted 6.12.0-rc2-syzkaller-g87d6aab2389e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_sock_timeout+0xa2/0x2d0 net/bluetooth/sco.c:140
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 5764:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:257 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2164
 sk_alloc+0x38/0x370 net/core/sock.c:2217
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:543 [inline]
 sco_sock_create+0xbb/0x390 net/bluetooth/sco.c:574
 bt_sock_create+0x163/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x492/0x920 net/socket.c:1576
 sock_create net/socket.c:1627 [inline]
 __sys_socket_create net/socket.c:1664 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1711
 __do_sys_socket net/socket.c:1725 [inline]
 __se_sys_socket net/socket.c:1723 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1723
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5765:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4727
 sk_prot_free net/core/sock.c:2200 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2292
 sco_sock_release+0x25e/0x320 net/bluetooth/sco.c:1302
 __sock_release net/socket.c:658 [inline]
 sock_close+0xbe/0x240 net/socket.c:1426
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:228
 get_signal+0x15e8/0x1740 kernel/signal.c:2690
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888140eac000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff888140eac000, ffff888140eac800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888140eab000 pfn:0x140ea8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000240(workingset|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000240 ffff888015442000 ffffea000515b410 ffffea000510e610
raw: ffff888140eab000 0000000000080006 00000001f5000000 0000000000000000
head: 057ff00000000240 ffff888015442000 ffffea000515b410 ffffea000510e610
head: ffff888140eab000 0000000000080006 00000001f5000000 0000000000000000
head: 057ff00000000003 ffffea000503aa01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2263006817, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 __kmalloc_cache_noprof+0x1d5/0x2c0 mm/slub.c:4290
 kmalloc_noprof include/linux/slab.h:878 [inline]
 kzalloc_noprof include/linux/slab.h:1014 [inline]
 acpi_ds_create_walk_state+0x103/0x2a0 drivers/acpi/acpica/dswstate.c:518
 acpi_ds_auto_serialize_method+0xe7/0x240 drivers/acpi/acpica/dsmethod.c:81
 acpi_ds_init_one_object+0x1bb/0x370 drivers/acpi/acpica/dsinit.c:110
 acpi_ns_walk_namespace+0x296/0x4f0
 acpi_ds_initialize_objects+0x199/0x2b0 drivers/acpi/acpica/dsinit.c:189
 acpi_ns_load_table+0xfd/0x120 drivers/acpi/acpica/nsload.c:106
 acpi_tb_load_namespace+0x291/0x6d0 drivers/acpi/acpica/tbxfload.c:158
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888140eabf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888140eac000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888140eac080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888140eac100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888140eac180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         87d6aab2 Merge tag 'for_linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=101aa707980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a5119ec8290b5433
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=124a3b80580000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_conn_del

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_conn_del+0xa5/0x310 net/bluetooth/sco.c:220
Write of size 4 at addr ffff88807bd72080 by task syz-executor.0/5406

CPU: 0 UID: 0 PID: 5406 Comm: syz-executor.0 Not tainted 6.12.0-rc4-syzkaller-gc2ee9f594da8-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:184 [inline]
 __refcount_inc include/linux/refcount.h:241 [inline]
 refcount_inc include/linux/refcount.h:258 [inline]
 sock_hold include/net/sock.h:781 [inline]
 sco_conn_del+0xa5/0x310 net/bluetooth/sco.c:220
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1975 [inline]
 hci_conn_hash_flush+0x101/0x240 net/bluetooth/hci_conn.c:2592
 hci_dev_close_sync+0x9ef/0x11a0 net/bluetooth/hci_sync.c:5195
 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline]
 hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2698
 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664
 __fput+0x241/0x880 fs/file_table.c:431
 task_work_run+0x251/0x310 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa2f/0x28e0 kernel/exit.c:939
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 __do_sys_exit_group kernel/exit.c:1099 [inline]
 __se_sys_exit_group kernel/exit.c:1097 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097
 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f018087de69
Code: Unable to access opcode bytes at 0x7f018087de3f.
RSP: 002b:00007fffa31fb468 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f018087de69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f01808ca45b R08: 00007fffa31f9207 R09: 000000000006d03d
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 000000000006d03d R14: 000000000006ccf5 R15: 0000000000000004
 </TASK>

Allocated by task 5400:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141
 getname_flags+0xb7/0x540 fs/namei.c:139
 getname fs/namei.c:225 [inline]
 __do_sys_unlink fs/namei.c:4581 [inline]
 __se_sys_unlink fs/namei.c:4579 [inline]
 __x64_sys_unlink+0x3a/0x50 fs/namei.c:4579
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5400:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kmem_cache_free+0x1a2/0x420 mm/slub.c:4681
 do_unlinkat+0x7b0/0x830 fs/namei.c:4556
 __do_sys_unlink fs/namei.c:4581 [inline]
 __se_sys_unlink fs/namei.c:4579 [inline]
 __x64_sys_unlink+0x47/0x50 fs/namei.c:4579
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807bd71100
 which belongs to the cache names_cache of size 4096
The buggy address is located 3968 bytes inside of
 freed 4096-byte region [ffff88807bd71100, ffff88807bd72100)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bd70
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff8880162f4780 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000070007 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff8880162f4780 dead000000000122 0000000000000000
head: 0000000000000000 0000000000070007 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0001ef5c01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5400, tgid 5400 (udevd), ts 432009536360, free_ts 431999575653
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x120 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4141
 getname_flags+0xb7/0x540 fs/namei.c:139
 vfs_fstatat+0x12c/0x190 fs/stat.c:340
 __do_sys_newfstatat fs/stat.c:505 [inline]
 __se_sys_newfstatat fs/stat.c:499 [inline]
 __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 4552 tgid 4552 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
 discard_slab mm/slub.c:2677 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:3145
 put_cpu_partial+0x17c/0x250 mm/slub.c:3220
 __slab_free+0x2ea/0x3d0 mm/slub.c:4449
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:247 [inline]
 slab_post_alloc_hook mm/slub.c:4085 [inline]
 slab_alloc_node mm/slub.c:4134 [inline]
 __do_kmalloc_node mm/slub.c:4263 [inline]
 __kmalloc_noprof+0x1a6/0x400 mm/slub.c:4276
 kmalloc_noprof include/linux/slab.h:882 [inline]
 tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822
 security_inode_getattr+0x130/0x330 security/security.c:2373
 vfs_getattr+0x45/0x430 fs/stat.c:204
 vfs_fstat fs/stat.c:229 [inline]
 vfs_fstatat+0xe4/0x190 fs/stat.c:338
 __do_sys_newfstatat fs/stat.c:505 [inline]
 __se_sys_newfstatat fs/stat.c:499 [inline]
 __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807bd71f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807bd72000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807bd72080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88807bd72100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88807bd72180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit:         c2ee9f59 KVM: selftests: Fix build on on non-x86 archi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=103ff430580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=346c6d758171538d
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13264a5f980000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
Tested-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com

Tested on:

commit:         c2ee9f59 KVM: selftests: Fix build on on non-x86 archi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a34a5f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=346c6d758171538d
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=101c0c30580000

Note: testing is done by a robot and is best-effort only.