2024-03-16 14:29:33

by syzbot

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Subject: [syzbot] [bluetooth?] possible deadlock in touch_wq_lockdep_map

Hello,

syzbot found the following issue on:

HEAD commit: 9187210eee7d Merge tag 'net-next-6.9' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=122856fa180000
kernel config: https://syzkaller.appspot.com/x/.config?x=222448ff79dba2ea
dashboard link: https://syzkaller.appspot.com/bug?extid=91dbdfecdd3287734d8e
compiler: gcc (Debian 12.2.0-14) 12.2.0, 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/98c1ea7ddb95/disk-9187210e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/343c5524f68f/vmlinux-9187210e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6c0c68b0ee90/bzImage-9187210e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

Bluetooth: hci0: Opcode 0x0c03 failed: -110
============================================
WARNING: possible recursive locking detected
6.8.0-syzkaller-05202-g9187210eee7d #0 Not tainted
--------------------------------------------
kworker/u9:5/13642 is trying to acquire lock:
ffff88803165d148 ((wq_completion)hci0){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x6e/0x120 kernel/workqueue.c:3901

but task is already holding lock:
ffff88803165d148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock((wq_completion)hci0);
lock((wq_completion)hci0);

*** DEADLOCK ***

May be due to missing lock nesting notation

2 locks held by kworker/u9:5/13642:
#0: ffff88803165d148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x1296/0x1a60 kernel/workqueue.c:3229
#1: ffffc90004d47d80 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work+0x906/0x1a60 kernel/workqueue.c:3230

stack backtrace:
CPU: 0 PID: 13642 Comm: kworker/u9:5 Not tainted 6.8.0-syzkaller-05202-g9187210eee7d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: hci0 hci_error_reset
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain kernel/locking/lockdep.c:3856 [inline]
__lock_acquire+0x20e6/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719
touch_wq_lockdep_map+0x78/0x120 kernel/workqueue.c:3901
__flush_workqueue+0x129/0x1200 kernel/workqueue.c:3943
drain_workqueue+0x18f/0x3d0 kernel/workqueue.c:4107
destroy_workqueue+0xc2/0xaa0 kernel/workqueue.c:5673
hci_release_dev+0x14e/0x660 net/bluetooth/hci_core.c:2808
bt_host_release+0x6a/0xb0 net/bluetooth/hci_sysfs.c:94
device_release+0xa1/0x240 drivers/base/core.c:2499
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1fa/0x5b0 lib/kobject.c:737
put_device+0x1f/0x30 drivers/base/core.c:3747
process_one_work+0x9a9/0x1a60 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:243
</TASK>


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