Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in __hci_req_sync

syzbot
2024-04-12T04:44:17Z

syzbot has found a reproducer for the following issue on:

HEAD commit: 00dcf5d862e8 Merge tag 'acpi-6.9-rc4' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15f84c93180000
kernel config: https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=27209997e4015fb4702e
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=179a3b4d180000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-00dcf5d8.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7a72277e36da/vmlinux-00dcf5d8.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5c529702b5e0/bzImage-00dcf5d8.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+27209997e4015fb4702e@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
BUG: KASAN: slab-use-after-free in refcount_read include/linux/refcount.h:136 [inline]
BUG: KASAN: slab-use-after-free in skb_unref include/linux/skbuff.h:1227 [inline]
BUG: KASAN: slab-use-after-free in __kfree_skb_reason net/core/skbuff.c:1224 [inline]
BUG: KASAN: slab-use-after-free in kfree_skb_reason+0x36/0x210 net/core/skbuff.c:1251
Read of size 4 at addr ffff88801d9c3b24 by task syz-executor.2/5302

CPU: 3 PID: 5302 Comm: syz-executor.2 Not tainted 6.9.0-rc3-syzkaller-00189-g00dcf5d862e8 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0xc3/0x620 mm/kasan/report.c:488
kasan_report+0xd9/0x110 mm/kasan/report.c:601
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:68 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
refcount_read include/linux/refcount.h:136 [inline]
skb_unref include/linux/skbuff.h:1227 [inline]
__kfree_skb_reason net/core/skbuff.c:1224 [inline]
kfree_skb_reason+0x36/0x210 net/core/skbuff.c:1251
kfree_skb include/linux/skbuff.h:1262 [inline]
__hci_req_sync+0x61d/0x980 net/bluetooth/hci_request.c:184
hci_req_sync+0x97/0xd0 net/bluetooth/hci_request.c:206
hci_dev_cmd+0x653/0x9c0 net/bluetooth/hci_core.c:790
hci_sock_ioctl+0x4f3/0x8e0 net/bluetooth/hci_sock.c:1153
sock_do_ioctl+0x116/0x280 net/socket.c:1222
sock_ioctl+0x22e/0x6c0 net/socket.c:1341
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl fs/ioctl.c:890 [inline]
__x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98e227dbcb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007fff8983d770 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f98e227dbcb
RDX: 00007fff8983d7e8 RSI: 00000000400448dd RDI: 0000000000000003
RBP: 0000555556cf6430 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000003 R14: 0000000000000001 R15: 00000000fffffff1
</TASK>

Allocated by task 5308:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:312 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3798 [inline]
slab_alloc_node mm/slub.c:3845 [inline]
kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
skb_clone+0x190/0x3f0 net/core/skbuff.c:2063
hci_send_cmd_sync net/bluetooth/hci_core.c:4220 [inline]
hci_cmd_work+0x66a/0x710 net/bluetooth/hci_core.c:4240
process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
kthread+0x2c1/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Freed by task 5308:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
poison_slab_object mm/kasan/common.c:240 [inline]
__kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2106 [inline]
slab_free mm/slub.c:4280 [inline]
kmem_cache_free+0x12e/0x380 mm/slub.c:4344
kfree_skbmem+0x10e/0x200 net/core/skbuff.c:1159
__kfree_skb net/core/skbuff.c:1217 [inline]
kfree_skb_reason+0x13a/0x210 net/core/skbuff.c:1252
kfree_skb include/linux/skbuff.h:1262 [inline]
hci_req_sync_complete+0x16c/0x270 net/bluetooth/hci_request.c:109
hci_event_packet+0x963/0x1170 net/bluetooth/hci_event.c:7604
hci_rx_work+0x2c4/0x1610 net/bluetooth/hci_core.c:4171
process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
kthread+0x2c1/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 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 ffff88801d9c3a40
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 228 bytes inside of
freed 240-byte region [ffff88801d9c3a40, ffff88801d9c3b30)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d9c2
head: order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000840 ffff888015b8e000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
head: 00fff80000000840 ffff888015b8e000 dead000000000122 0000000000000000
head: 0000000000000000 0000000000190019 00000001ffffffff 0000000000000000
head: 00fff80000000001 ffffea0000767081 dead000000000122 00000000ffffffff
head: 0000000200000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5314, tgid 5314 (kworker/u33:8), ts 1081717469726, free_ts 1081659697828
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
prep_new_page mm/page_alloc.c:1541 [inline]
get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
__alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
__alloc_pages_node include/linux/gfp.h:238 [inline]
alloc_pages_node include/linux/gfp.h:261 [inline]
alloc_slab_page mm/slub.c:2175 [inline]
allocate_slab mm/slub.c:2338 [inline]
new_slab+0xcc/0x3a0 mm/slub.c:2391
___slab_alloc+0x66d/0x1790 mm/slub.c:3525
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
__slab_alloc_node mm/slub.c:3663 [inline]
slab_alloc_node mm/slub.c:3835 [inline]
kmem_cache_alloc+0x2e9/0x320 mm/slub.c:3852
skb_clone+0x190/0x3f0 net/core/skbuff.c:2063
hci_send_cmd_sync net/bluetooth/hci_core.c:4220 [inline]
hci_cmd_work+0x66a/0x710 net/bluetooth/hci_core.c:4240
process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
process_scheduled_works kernel/workqueue.c:3335 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
kthread+0x2c1/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page last free pid 5294 tgid 5294 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1141 [inline]
free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3798 [inline]
slab_alloc_node mm/slub.c:3845 [inline]
kmalloc_trace+0x147/0x330 mm/slub.c:3992
kmalloc include/linux/slab.h:628 [inline]
kzalloc include/linux/slab.h:749 [inline]
tomoyo_print_bprm security/tomoyo/audit.c:26 [inline]
tomoyo_init_log+0xcb6/0x2180 security/tomoyo/audit.c:264
tomoyo_supervisor+0x30c/0xea0 security/tomoyo/common.c:2089
tomoyo_audit_env_log security/tomoyo/environ.c:36 [inline]
tomoyo_env_perm+0x193/0x210 security/tomoyo/environ.c:63
tomoyo_environ security/tomoyo/domain.c:672 [inline]
tomoyo_find_next_domain+0xef9/0x2020 security/tomoyo/domain.c:878
tomoyo_bprm_check_security security/tomoyo/tomoyo.c:102 [inline]
tomoyo_bprm_check_security+0x12e/0x1d0 security/tomoyo/tomoyo.c:92
security_bprm_check+0x65/0xb0 security/security.c:1191
search_binary_handler fs/exec.c:1766 [inline]
exec_binprm fs/exec.c:1820 [inline]
bprm_execve fs/exec.c:1872 [inline]
bprm_execve+0x642/0x19b0 fs/exec.c:1848
do_execveat_common.isra.0+0x5cb/0x750 fs/exec.c:1979
do_execve fs/exec.c:2053 [inline]
__do_sys_execve fs/exec.c:2129 [inline]
__se_sys_execve fs/exec.c:2124 [inline]
__x64_sys_execve+0x8c/0xb0 fs/exec.c:2124
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83

Memory state around the buggy address:
ffff88801d9c3a00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
ffff88801d9c3a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801d9c3b00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
^
ffff88801d9c3b80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801d9c3c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
==================================================================

---
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#syz test: git://repo/address.git branch-or-commit-hash
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