linux-kernel - [syzbot] [bluetooth?] possible deadlock in touch_wq_lockdep

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Message-ID: <6708ea92.050a0220.4cbc0.0000.GAE@google.com>
Date: Fri, 11 Oct 2024 02:06:26 -0700
From: syzbot <syzbot+7386bb3da86fa8113f70@...kaller.appspotmail.com>
To: johan.hedberg@...il.com, linux-bluetooth@...r.kernel.org, 
	linux-kernel@...r.kernel.org, luiz.dentz@...il.com, marcel@...tmann.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bluetooth?] possible deadlock in touch_wq_lockdep_map (2)

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@...kaller.appspotmail.com

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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