[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in skb_queue_purge_reason (2)

syzbot
2024-05-17T08:44:24Z

Hello,

syzbot found the following issue on:

HEAD commit: 621cde16e49b Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=14b6fa84980000
kernel config: https://syzkaller.appspot.com/x/.config?x=bddb81daac38d475
dashboard link: https://syzkaller.appspot.com/bug?extid=683f8cb11b94b1824c77
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9591b45993bc/disk-621cde16.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2a31801cab2a/vmlinux-621cde16.xz
kernel image: https://storage.googleapis.com/syzbot-assets/37962f7be4eb/bzImage-621cde16.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+683f8cb11b94b1824c77@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1840 [inline]
BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0xb9/0x500 net/core/skbuff.c:3877
Read of size 8 at addr ffff8880118db058 by task syz-executor.1/9233

CPU: 1 PID: 9233 Comm: syz-executor.1 Not tainted 6.9.0-syzkaller-05156-g621cde16e49b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
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
skb_queue_empty_lockless include/linux/skbuff.h:1840 [inline]
skb_queue_purge_reason+0xb9/0x500 net/core/skbuff.c:3877
skb_queue_purge include/linux/skbuff.h:3273 [inline]
vhci_flush+0x44/0x50 drivers/bluetooth/hci_vhci.c:69
hci_dev_do_reset net/bluetooth/hci_core.c:625 [inline]
hci_dev_reset+0x42a/0x5d0 net/bluetooth/hci_core.c:665
sock_do_ioctl+0x158/0x460 net/socket.c:1222
sock_ioctl+0x629/0x8e0 net/socket.c:1341
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdbb787cee9
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:00007fdbb85530c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fdbb79abf80 RCX: 00007fdbb787cee9
RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000006
RBP: 00007fdbb78c949e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fdbb79abf80 R15: 00007ffea6376cb8
</TASK>

Allocated by task 8951:
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:370 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
kasan_kmalloc include/linux/kasan.h:211 [inline]
kmalloc_trace+0x1db/0x370 mm/slub.c:4070
kmalloc include/linux/slab.h:628 [inline]
kzalloc include/linux/slab.h:749 [inline]
vhci_open+0x57/0x370 drivers/bluetooth/hci_vhci.c:636
misc_open+0x313/0x390 drivers/char/misc.c:165
chrdev_open+0x5b0/0x630 fs/char_dev.c:414
do_dentry_open+0x907/0x15a0 fs/open.c:955
do_open fs/namei.c:3650 [inline]
path_openat+0x2860/0x3240 fs/namei.c:3807
do_filp_open+0x235/0x490 fs/namei.c:3834
do_sys_openat2+0x13e/0x1d0 fs/open.c:1406
do_sys_open fs/open.c:1421 [inline]
__do_sys_openat fs/open.c:1437 [inline]
__se_sys_openat fs/open.c:1432 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1432
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 8951:
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+0xa6/0xe0 mm/kasan/common.c:240
__kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
kasan_slab_free include/linux/kasan.h:184 [inline]
slab_free_hook mm/slub.c:2121 [inline]
slab_free mm/slub.c:4353 [inline]
kfree+0x153/0x3b0 mm/slub.c:4463
vhci_release+0xbf/0xd0 drivers/bluetooth/hci_vhci.c:672
__fput+0x429/0x8a0 fs/file_table.c:422
task_work_run+0x24f/0x310 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa1b/0x27e0 kernel/exit.c:878
do_group_exit+0x207/0x2c0 kernel/exit.c:1027
__do_sys_exit_group kernel/exit.c:1038 [inline]
__se_sys_exit_group kernel/exit.c:1036 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880118db000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 88 bytes inside of
freed 1024-byte region [ffff8880118db000, ffff8880118db400)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x118d8
head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888015041dc0 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
head: 00fff00000000840 ffff888015041dc0 0000000000000000 dead000000000001
head: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
head: 00fff00000000003 ffffea0000463601 dead000000000122 00000000ffffffff
head: 0000000800000000 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 4793, tgid 4793 (dhcpcd), ts 31626179552, free_ts 31588472252
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
prep_new_page mm/page_alloc.c:1541 [inline]
get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
__alloc_pages+0x256/0x6c0 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+0x5f/0x160 mm/slub.c:2190
allocate_slab mm/slub.c:2353 [inline]
new_slab+0x84/0x2f0 mm/slub.c:2406
___slab_alloc+0xb07/0x12e0 mm/slub.c:3592
__slab_alloc mm/slub.c:3682 [inline]
__slab_alloc_node mm/slub.c:3735 [inline]
slab_alloc_node mm/slub.c:3908 [inline]
__do_kmalloc_node mm/slub.c:4038 [inline]
__kmalloc+0x2e5/0x4a0 mm/slub.c:4052
kmalloc include/linux/slab.h:632 [inline]
load_elf_phdrs fs/binfmt_elf.c:526 [inline]
load_elf_binary+0x2f4/0x2660 fs/binfmt_elf.c:855
search_binary_handler fs/exec.c:1786 [inline]
exec_binprm fs/exec.c:1828 [inline]
bprm_execve+0xaf8/0x17c0 fs/exec.c:1880
do_execveat_common+0x553/0x700 fs/exec.c:1987
do_execve fs/exec.c:2061 [inline]
__do_sys_execve fs/exec.c:2137 [inline]
__se_sys_execve fs/exec.c:2132 [inline]
__x64_sys_execve+0x92/0xb0 fs/exec.c:2132
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 4791 tgid 4791 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+0x986/0xab0 mm/page_alloc.c:2347
free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
discard_slab mm/slub.c:2452 [inline]
__put_partials+0xeb/0x130 mm/slub.c:2920
put_cpu_partial+0x17c/0x250 mm/slub.c:2995
__slab_free+0x2ea/0x3d0 mm/slub.c:4224
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x5e/0xc0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3871 [inline]
slab_alloc_node mm/slub.c:3918 [inline]
kmem_cache_alloc+0x174/0x350 mm/slub.c:3925
getname_flags+0xbd/0x4f0 fs/namei.c:139
vfs_fstatat+0x11c/0x190 fs/stat.c:303
__do_sys_newfstatat fs/stat.c:468 [inline]
__se_sys_newfstatat fs/stat.c:462 [inline]
__x64_sys_newfstatat+0x125/0x1b0 fs/stat.c:462
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff8880118daf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880118daf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880118db000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880118db080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880118db100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
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