syzbot


possible deadlock in touch_wq_lockdep_map (2)

Status: upstream: reported on 2024/10/11 09:06
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+7386bb3da86fa8113f70@syzkaller.appspotmail.com
First crash: 34d, last: 20d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] possible deadlock in touch_wq_lockdep_map (2) 0 (1) 2024/10/11 09:06
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in touch_wq_lockdep_map usb C 1208 43d 239d 28/28 fixed on 2024/10/03 15:25

Sample crash report:
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>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/09 22:32 upstream 75b607fab38d 0278d004 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in touch_wq_lockdep_map
2024/10/21 07:24 upstream db87114dcf13 cd6fc0a3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in touch_wq_lockdep_map
2024/10/07 11:35 upstream 8cf0b93919e1 d7906eff .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in touch_wq_lockdep_map
2024/10/13 14:15 upstream 36c254515dc6 084d8178 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in touch_wq_lockdep_map
2024/10/07 08:59 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 80cb3fb61135 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 possible deadlock in touch_wq_lockdep_map
* Struck through repros no longer work on HEAD.