[v6.6] WARNING: ODEBUG bug in bt_host_release

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0a805b6ea8cd Linux 6.6.116
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1060c914580000
kernel config: https://syzkaller.appspot.com/x/.config?x=12606d4b8832c7e4
dashboard link: https://syzkaller.appspot.com/bug?extid=5e2d7111f84f8ec4b492
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/13874446b4b2/disk-0a805b6e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/69a5e59e1ade/vmlinux-0a805b6e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/322c0711f976/bzImage-0a805b6e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5e2d71...@syzkaller.appspotmail.com

Bluetooth: hci0: Opcode 0x080f failed: -4
------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff88805fc389c0 object type: timer_list hint: hci_cmd_timeout+0x0/0x1e0
WARNING: CPU: 1 PID: 12192 at lib/debugobjects.c:518 debug_print_object lib/debugobjects.c:515 [inline]
WARNING: CPU: 1 PID: 12192 at lib/debugobjects.c:518 __debug_check_no_obj_freed lib/debugobjects.c:990 [inline]
WARNING: CPU: 1 PID: 12192 at lib/debugobjects.c:518 debug_check_no_obj_freed+0x446/0x540 lib/debugobjects.c:1020
Modules linked in:
CPU: 1 PID: 12192 Comm: syz.4.2313 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:debug_print_object lib/debugobjects.c:515 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:990 [inline]
RIP: 0010:debug_check_no_obj_freed+0x446/0x540 lib/debugobjects.c:1020
Code: 4c 8b 4d 00 48 c7 c7 c0 74 fc 8a 48 c7 c6 20 71 fc 8a 48 c7 c2 40 76 fc 8a 8b 0c 24 4d 89 f8 41 55 e8 6e dd 29 fd 48 83 c4 08 <0f> 0b 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc ff df ff 05 a3 92 24
RSP: 0018:ffffc900034f7a38 EFLAGS: 00010282
RAX: b073de4d2e5ea500 RBX: ffffffff970729b8 RCX: 0000000000080000
RDX: ffffc90018a6d000 RSI: 0000000000008445 RDI: 0000000000008446
RBP: ffffffff8aac9f00 R08: ffffc900034f7627 R09: 1ffff9200069eec4
R10: dffffc0000000000 R11: fffff5200069eec5 R12: ffff88805fc3a000
R13: ffffffff89702a60 R14: ffff88805fc38000 R15: ffff88805fc389c0
FS: 00007f739ab766c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4bca459e9c CR3: 00000000674af000 CR4: 00000000003506e0
Call Trace:
<TASK>
slab_free_hook mm/slub.c:1786 [inline]
slab_free_freelist_hook+0xd2/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
bt_host_release+0x82/0x90 net/bluetooth/hci_sysfs.c:87
device_release+0x96/0x1c0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x221/0x470 lib/kobject.c:737
hci_dev_put include/net/bluetooth/hci_core.h:1610 [inline]
hci_dev_cmd+0x213/0x7b0 net/bluetooth/hci_core.c:803
sock_do_ioctl+0xd7/0x2f0 net/socket.c:1222
sock_ioctl+0x623/0x7a0 net/socket.c:1341
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7399d8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f739ab76038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7399fe5fa0 RCX: 00007f7399d8f6c9
RDX: 00002000000001c0 RSI: 00000000400448e1 RDI: 0000000000000004
RBP: 00007f7399e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7399fe6038 R14: 00007f7399fe5fa0 R15: 00007ffdfb5803b8
</TASK>


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