[v5.15] WARNING: ODEBUG bug in hci_release_dev (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 68efe5a6c16a Linux 5.15.197
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1653ddb4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e6ed99963d6ee1d
dashboard link: https://syzkaller.appspot.com/bug?extid=cb29004d5475e6345cd4
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/900f9b9bd850/disk-68efe5a6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1e089a5019a6/vmlinux-68efe5a6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b319f477b907/bzImage-68efe5a6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cb2900...@syzkaller.appspotmail.com

------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x80
WARNING: CPU: 1 PID: 4183 at lib/debugobjects.c:521 debug_print_object lib/debugobjects.c:518 [inline]
WARNING: CPU: 1 PID: 4183 at lib/debugobjects.c:521 __debug_check_no_obj_freed lib/debugobjects.c:973 [inline]
WARNING: CPU: 1 PID: 4183 at lib/debugobjects.c:521 debug_check_no_obj_freed+0x43c/0x530 lib/debugobjects.c:1003
Modules linked in:
CPU: 0 PID: 4183 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:debug_print_object lib/debugobjects.c:518 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:973 [inline]
RIP: 0010:debug_check_no_obj_freed+0x43c/0x530 lib/debugobjects.c:1003
Code: ef e8 c8 fd dc fd 4c 8b 45 00 48 c7 c7 20 f1 59 8a 48 c7 c6 e0 ed 59 8a 48 c7 c2 80 f2 59 8a 8b 0c 24 4d 89 e9 e8 e4 f0 b7 05 <0f> 0b 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc ff df ff 05 45 32 8a
RSP: 0018:ffffc90002e9f9e0 EFLAGS: 00010246
RAX: b779fd485fc8f500 RBX: ffffffff9628d4f0 RCX: ffff888079cc9dc0
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffffff8a0c9cc0 R08: dffffc0000000000 R09: ffffed10172267b0
R10: ffffed10172267b0 R11: 1ffff110172267af R12: ffff888079af6000
R13: ffffffff814d19c0 R14: ffff888079af4000 R15: ffff888079af4798
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a7606a13b8 CR3: 000000002b4ec000 CR4: 00000000003506f0
Call Trace:
<TASK>
slab_free_hook mm/slub.c:1685 [inline]
slab_free_freelist_hook+0x8b/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kfree+0xef/0x2a0 mm/slub.c:4564
hci_release_dev+0x1378/0x14e0 net/bluetooth/hci_core.c:4096
bt_host_release+0x7e/0x90 net/bluetooth/hci_sysfs.c:85
device_release+0x92/0x1c0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:713 [inline]
kobject_release lib/kobject.c:744 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x21d/0x460 lib/kobject.c:761
vhci_release+0x7b/0xc0 drivers/bluetooth/hci_vhci.c:346
__fput+0x234/0x930 fs/file_table.c:311
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x61e/0x20a0 kernel/exit.c:883
do_group_exit+0x12e/0x300 kernel/exit.c:997
__do_sys_exit_group kernel/exit.c:1008 [inline]
__se_sys_exit_group kernel/exit.c:1006 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fead06eb749
Code: Unable to access opcode bytes at RIP 0x7fead06eb71f.
RSP: 002b:00007ffe5f9a9d98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fead076fda2 RCX: 00007fead06eb749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000005 R08: 00007ffe5f9a7b37 R09: 00007ffe5f9ab050
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe5f9ab050
R13: 00007fead076fd7d R14: 000000000001bb55 R15: 00007ffe5f9ad210
</TASK>


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