[syzbot] [bluetooth?] possible deadlock in touch_wq_lockdep_map (2)

From: syzbot
Date: Fri Oct 11 2024 - 05:06:34 EST


Hello,

syzbot found the following issue on:

HEAD commit: 75b607fab38d Merge tag 'sched_ext-for-6.12-rc2-fixes' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1494b7d0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7cd9e7e4a8a0a15b
dashboard link: https://syzkaller.appspot.com/bug?extid=7386bb3da86fa8113f70
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/001d5437d70d/disk-75b607fa.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4c93454dd9e4/vmlinux-75b607fa.xz
kernel image: https://storage.googleapis.com/syzbot-assets/dc2a448f02b5/bzImage-75b607fa.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7386bb3da86fa8113f70@xxxxxxxxxxxxxxxxxxxxxxxxx

Bluetooth: hci1: Controller not accepting commands anymore: ncmd = 0
Bluetooth: hci1: Injecting HCI hardware error event
Bluetooth: hci1: hardware error 0x00
============================================
WARNING: possible recursive locking detected
6.12.0-rc2-syzkaller-00058-g75b607fab38d #0 Not tainted
--------------------------------------------
kworker/u9:1/9530 is trying to acquire lock:
ffff888037f87148 ((wq_completion)hci1){+.+.}-{0:0}, at: touch_wq_lockdep_map+0xb1/0x170 kernel/workqueue.c:3880

but task is already holding lock:
ffff888037f87148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
ffff888037f87148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310

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

CPU0
----
lock((wq_completion)hci1);
lock((wq_completion)hci1);

*** DEADLOCK ***

May be due to missing lock nesting notation

2 locks held by kworker/u9:1/9530:
#0: ffff888037f87148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
#0: ffff888037f87148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
#1: ffffc900043e7d00 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
#1: ffffc900043e7d00 ((work_completion)(&hdev->error_reset)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310

stack backtrace:
CPU: 0 UID: 0 PID: 9530 Comm: kworker/u9:1 Not tainted 6.12.0-rc2-syzkaller-00058-g75b607fab38d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: hci1 hci_error_reset
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
check_deadlock kernel/locking/lockdep.c:3089 [inline]
validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
__lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
touch_wq_lockdep_map+0xc7/0x170 kernel/workqueue.c:3880
__flush_workqueue+0x14f/0x1600 kernel/workqueue.c:3922
drain_workqueue+0xc9/0x3a0 kernel/workqueue.c:4086
destroy_workqueue+0xba/0xc40 kernel/workqueue.c:5830
hci_release_dev+0x169/0x16b0 net/bluetooth/hci_core.c:2733
bt_host_release+0x83/0x90 net/bluetooth/hci_sysfs.c:94
device_release+0x9b/0x1c0
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x231/0x480 lib/kobject.c:737
process_one_work kernel/workqueue.c:3229 [inline]
process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310
worker_thread+0x870/0xd30 kernel/workqueue.c:3391
kthread+0x2f2/0x390 kernel/kthread.c:389
ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>


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