syzbot


INFO: task hung in synchronize_rcu

Status: upstream: reported C repro on 2023/04/01 04:49
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+a7cb7d83f9a1ddae7487@syzkaller.appspotmail.com
First crash: 688d, last: 22d
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: INFO: rcu detected stall in corrupted (log)
Repro: C syz .config
  
Bug presence (2)
Date Name Commit Repro Result
2023/05/11 linux-6.1.y (ToT) ca48fc16c493 C [report] INFO: rcu detected stall in corrupted
2023/05/11 upstream (ToT) 80e62bc8487b C Didn't crash
Similar bugs (11)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in synchronize_rcu (3) C done done 374 733d 1671d 22/28 fixed on 2023/02/24 13:50
android-49 INFO: task hung in synchronize_rcu 1 1907d 1907d 0/3 auto-closed as invalid on 2020/03/28 16:57
linux-4.14 INFO: task hung in synchronize_rcu vfs C error 162 748d 1929d 0/1 upstream: reported C repro on 2019/11/07 04:32
linux-4.19 INFO: task hung in synchronize_rcu C error 70 737d 1928d 0/1 upstream: reported C repro on 2019/11/08 21:27
linux-5.15 INFO: task hung in synchronize_rcu 1 674d 674d 0/3 auto-obsoleted due to no activity on 2023/08/14 02:05
linux-5.15 INFO: task hung in synchronize_rcu (3) origin:lts-only C error 10 71d 206d 0/3 upstream: reported C repro on 2024/07/26 03:55
upstream INFO: task hung in synchronize_rcu syz done 1206 1907d 1933d 14/28 fixed on 2019/11/29 15:48
upstream INFO: task hung in synchronize_rcu (4) net fs C done error 884 16d 656d 0/28 upstream: reported C repro on 2023/05/04 02:01
linux-5.15 INFO: task hung in synchronize_rcu (2) 1 362d 362d 0/3 auto-obsoleted due to no activity on 2024/05/31 13:53
android-414 INFO: task hung in synchronize_rcu 1 1925d 1925d 0/1 auto-closed as invalid on 2020/03/10 10:42
upstream INFO: task hung in synchronize_rcu (2) trace 8 1906d 1907d 0/28 closed as invalid on 2019/11/30 16:54
Fix bisection attempts (6)
Created Duration User Patch Repo Result
2023/11/04 15:56 6h51m fix candidate upstream OK (1) job log
2023/10/20 14:20 2h47m bisect fix linux-6.1.y OK (0) job log log
2023/09/15 19:01 2h03m bisect fix linux-6.1.y OK (0) job log log
2023/07/01 18:15 1h18m bisect fix linux-6.1.y OK (0) job log log
2023/06/01 08:18 1h16m bisect fix linux-6.1.y OK (0) job log log
2023/05/01 15:41 1h03m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
INFO: task kworker/0:1:14 blocked for more than 143 seconds.
      Not tainted 6.1.123-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1     state:D stack:20448 pid:14    ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline]
 synchronize_rcu_expedited+0x819/0x930 kernel/rcu/tree_exp.h:962
 synchronize_rcu+0x11c/0x3f0 kernel/rcu/tree.c:3576
 lockdep_unregister_key+0x54b/0x600 kernel/locking/lockdep.c:6371
 wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
 destroy_workqueue+0x81f/0xae0 kernel/workqueue.c:4469
 ath6kl_usb_destroy+0x341/0x360 drivers/net/wireless/ath/ath6kl/usb.c:623
 ath6kl_usb_probe+0x1283/0x1320 drivers/net/wireless/ath/ath6kl/usb.c:1179
 usb_probe_interface+0x5c0/0xaf0 drivers/usb/core/driver.c:396
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_set_configuration+0x19dd/0x2020 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x84/0x140 drivers/usb/core/generic.c:238
 usb_probe_device+0x130/0x260 drivers/usb/core/driver.c:293
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_new_device+0xbdd/0x18f0 drivers/usb/core/hub.c:2620
 hub_port_connect drivers/usb/core/hub.c:5477 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5617 [inline]
 port_event drivers/usb/core/hub.c:5773 [inline]
 hub_event+0x2efe/0x5730 drivers/usb/core/hub.c:5855
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xd04/0x1200 kernel/workqueue.c:2441
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task kworker/1:1:32 blocked for more than 144 seconds.
      Not tainted 6.1.123-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:1     state:D stack:21624 pid:32    ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline]
 synchronize_rcu_expedited+0x819/0x930 kernel/rcu/tree_exp.h:962
 synchronize_rcu+0x11c/0x3f0 kernel/rcu/tree.c:3576
 lockdep_unregister_key+0x54b/0x600 kernel/locking/lockdep.c:6371
 wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
 destroy_workqueue+0x81f/0xae0 kernel/workqueue.c:4469
 ath6kl_usb_destroy+0x341/0x360 drivers/net/wireless/ath/ath6kl/usb.c:623
 ath6kl_usb_probe+0x1283/0x1320 drivers/net/wireless/ath/ath6kl/usb.c:1179
 usb_probe_interface+0x5c0/0xaf0 drivers/usb/core/driver.c:396
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_set_configuration+0x19dd/0x2020 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x84/0x140 drivers/usb/core/generic.c:238
 usb_probe_device+0x130/0x260 drivers/usb/core/driver.c:293
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_new_device+0xbdd/0x18f0 drivers/usb/core/hub.c:2620
 hub_port_connect drivers/usb/core/hub.c:5477 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5617 [inline]
 port_event drivers/usb/core/hub.c:5773 [inline]
 hub_event+0x2efe/0x5730 drivers/usb/core/hub.c:5855
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xd04/0x1200 kernel/workqueue.c:2441
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task kworker/0:2:126 blocked for more than 144 seconds.
      Not tainted 6.1.123-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2     state:D stack:21080 pid:126   ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6693
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747
 exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
 synchronize_rcu+0x11c/0x3f0 kernel/rcu/tree.c:3576
 lockdep_unregister_key+0x54b/0x600 kernel/locking/lockdep.c:6371
 wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
 destroy_workqueue+0x81f/0xae0 kernel/workqueue.c:4469
 ath6kl_usb_destroy+0x341/0x360 drivers/net/wireless/ath/ath6kl/usb.c:623
 ath6kl_usb_probe+0x1283/0x1320 drivers/net/wireless/ath/ath6kl/usb.c:1179
 usb_probe_interface+0x5c0/0xaf0 drivers/usb/core/driver.c:396
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_set_configuration+0x19dd/0x2020 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x84/0x140 drivers/usb/core/generic.c:238
 usb_probe_device+0x130/0x260 drivers/usb/core/driver.c:293
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_new_device+0xbdd/0x18f0 drivers/usb/core/hub.c:2620
 hub_port_connect drivers/usb/core/hub.c:5477 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5617 [inline]
 port_event drivers/usb/core/hub.c:5773 [inline]
 hub_event+0x2efe/0x5730 drivers/usb/core/hub.c:5855
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xd04/0x1200 kernel/workqueue.c:2441
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task kworker/1:2:3582 blocked for more than 145 seconds.
      Not tainted 6.1.123-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2     state:D stack:21080 pid:3582  ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 synchronize_rcu_expedited+0x777/0x930 kernel/rcu/tree_exp.h:977
 synchronize_rcu+0x11c/0x3f0 kernel/rcu/tree.c:3576
 lockdep_unregister_key+0x54b/0x600 kernel/locking/lockdep.c:6371
 wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
 destroy_workqueue+0x81f/0xae0 kernel/workqueue.c:4469
 ath6kl_usb_destroy+0x341/0x360 drivers/net/wireless/ath/ath6kl/usb.c:623
 ath6kl_usb_probe+0x1283/0x1320 drivers/net/wireless/ath/ath6kl/usb.c:1179
 usb_probe_interface+0x5c0/0xaf0 drivers/usb/core/driver.c:396
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_set_configuration+0x19dd/0x2020 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x84/0x140 drivers/usb/core/generic.c:238
 usb_probe_device+0x130/0x260 drivers/usb/core/driver.c:293
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_new_device+0xbdd/0x18f0 drivers/usb/core/hub.c:2620
 hub_port_connect drivers/usb/core/hub.c:5477 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5617 [inline]
 port_event drivers/usb/core/hub.c:5773 [inline]
 hub_event+0x2efe/0x5730 drivers/usb/core/hub.c:5855
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xd04/0x1200 kernel/workqueue.c:2441
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task kworker/0:3:4277 blocked for more than 146 seconds.
      Not tainted 6.1.123-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D stack:26560 pid:4277  ppid:2      flags:0x00004000
Workqueue: events pwq_unbound_release_workfn
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline]
 synchronize_rcu_expedited+0x819/0x930 kernel/rcu/tree_exp.h:962
 synchronize_rcu+0x11c/0x3f0 kernel/rcu/tree.c:3576
 lockdep_unregister_key+0x54b/0x600 kernel/locking/lockdep.c:6371
 wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
 pwq_unbound_release_workfn+0x23d/0x290 kernel/workqueue.c:3738
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task kworker/0:5:4296 blocked for more than 146 seconds.
      Not tainted 6.1.123-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:5     state:D stack:27800 pid:4296  ppid:2      flags:0x00004000
Workqueue: events pwq_unbound_release_workfn
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline]
 synchronize_rcu_expedited+0x819/0x930 kernel/rcu/tree_exp.h:962
 synchronize_rcu+0x11c/0x3f0 kernel/rcu/tree.c:3576
 lockdep_unregister_key+0x54b/0x600 kernel/locking/lockdep.c:6371
 wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
 pwq_unbound_release_workfn+0x23d/0x290 kernel/workqueue.c:3738
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d32b290 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d32ba90 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
5 locks held by kworker/0:1/14:
 #0: ffff888142af8538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000137d20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff888144bfa190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #2: ffff888144bfa190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5730 drivers/usb/core/hub.c:5801
 #3: ffff88807c79e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #3: ffff88807c79e190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
 #4: ffff8880735b9118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #4: ffff8880735b9118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
6 locks held by kworker/1:0/22:
1 lock held by khungtaskd/27:
 #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
5 locks held by kworker/1:1/32:
 #0: ffff888142af8538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90000a8fd20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff8880283f2190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #2: ffff8880283f2190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5730 drivers/usb/core/hub.c:5801
 #3: ffff888142aa9190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #3: ffff888142aa9190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
 #4: ffff888142aaa118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #4: ffff888142aaa118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
6 locks held by kworker/0:2/126:
 #0: ffff888142af8538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90002e17d20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff88802840a190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #2: ffff88802840a190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5730 drivers/usb/core/hub.c:5801
 #3: ffff88807c79f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #3: ffff88807c79f190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
 #4: ffff88807c798118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #4: ffff88807c798118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
 #5: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #5: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
6 locks held by kworker/1:2/3582:
 #0: ffff888142af8538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc9000df97d20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #2: ffff888144b2c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #2: ffff888144b2c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5730 drivers/usb/core/hub.c:5801
 #3: ffff888079067190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #3: ffff888079067190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
 #4: ffff88807da59118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline]
 #4: ffff88807da59118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990
 #5: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #5: ffffffff8d3306b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962
2 locks held by getty/4009:
 #0: ffff888030c4b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:3/4277:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90003f37d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
2 locks held by kworker/0:5/4296:
 #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
 #1: ffffc90003ed7d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267
1 lock held by dhcpcd/4522:
 #0: ffff888148b98130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline]
 #0: ffff888148b98130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd00 net/packet/af_packet.c:3263
1 lock held by dhcpcd/4523:
 #0: ffff888148b9c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline]
 #0: ffff888148b9c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd00 net/packet/af_packet.c:3263
1 lock held by dhcpcd/4524:
 #0: ffff88814bc68130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline]
 #0: ffff88814bc68130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd00 net/packet/af_packet.c:3263
1 lock held by dhcpcd/4525:
 #0: ffff888142f4a130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline]
 #0: ffff888142f4a130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd00 net/packet/af_packet.c:3263
1 lock held by dhcpcd/4526:
 #0: ffff8881433d6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline]
 #0: ffff8881433d6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd00 net/packet/af_packet.c:3263
1 lock held by dhcpcd/4527:
 #0: ffff8881433d2130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline]
 #0: ffff8881433d2130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd00 net/packet/af_packet.c:3263

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf88/0xfd0 kernel/hung_task.c:377
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 22 Comm: kworker/1:0 Not tainted 6.1.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: usb_hub_wq hub_event
RIP: 0010:preempt_count_sub+0x2e/0x160 kernel/sched/core.c:5734
Code: fb 48 c7 c0 60 61 35 97 48 c1 e8 03 49 be 00 00 00 00 00 fc ff df 42 0f b6 04 30 84 c0 0f 85 c0 00 00 00 83 3d 92 d1 d6 15 00 <75> 22 65 8b 05 71 df a3 7e 89 c1 81 e1 ff ff ff 7f 39 d9 7c 23 81
RSP: 0018:ffffc900001e0328 EFLAGS: 00000046
RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff97356103
RDX: dffffc0000000000 RSI: ffffc900001c0000 RDI: 0000000000000001
RBP: ffffc900001e0420 R08: ffffc900001c6730 R09: ffffc900001e0470
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc900001e0420
R13: ffffffff8f159f48 R14: dffffc0000000000 R15: ffffc900001c6740
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0f07ca9690 CR3: 000000007c028000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 unwind_next_frame+0x1a3f/0x2220 arch/x86/kernel/unwind_orc.c:629
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 ath6kl_usb_cleanup_recv_urb drivers/net/wireless/ath/ath6kl/usb.c:171 [inline]
 ath6kl_usb_recv_complete+0x1ea/0x4c0 drivers/net/wireless/ath/ath6kl/usb.c:551
 __usb_hcd_giveback_urb+0x371/0x530 drivers/usb/core/hcd.c:1675
 dummy_timer+0x8dc/0x32b0 drivers/usb/gadget/udc/dummy_hcd.c:1994
 __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
 __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1753
 hrtimer_run_softirq+0x196/0x2c0 kernel/time/hrtimer.c:1770
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571
 __do_softirq kernel/softirq.c:605 [inline]
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65
Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01
RSP: 0018:ffffc900001c65b8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 1ffffffff1eae956 RCX: 0000000000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900001c6700
RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffc900001c66f0
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc900001c66a0
R13: ffffffff8f574ab2 R14: ffffc900001c66d5 R15: ffffc900001c66f0
 unwind_next_frame+0xde7/0x2220 arch/x86/kernel/unwind_orc.c:546
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x97/0xb0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:936 [inline]
 __kmalloc_node_track_caller+0xb1/0x220 mm/slab_common.c:956
 kmalloc_reserve net/core/skbuff.c:446 [inline]
 __alloc_skb+0x135/0x670 net/core/skbuff.c:515
 __netdev_alloc_skb+0xfb/0x500 net/core/skbuff.c:579
 netdev_alloc_skb include/linux/skbuff.h:3206 [inline]
 dev_alloc_skb include/linux/skbuff.h:3219 [inline]
 ath6kl_usb_post_recv_transfers+0x218/0x6c0 drivers/net/wireless/ath/ath6kl/usb.c:428
 ath6kl_usb_start_recv_pipes drivers/net/wireless/ath/ath6kl/usb.c:498 [inline]
 hif_start drivers/net/wireless/ath/ath6kl/usb.c:703 [inline]
 ath6kl_usb_power_on+0x69/0x270 drivers/net/wireless/ath/ath6kl/usb.c:1062
 ath6kl_hif_power_on drivers/net/wireless/ath/ath6kl/hif-ops.h:136 [inline]
 ath6kl_core_init+0x1b9/0x1120 drivers/net/wireless/ath/ath6kl/core.c:97
 ath6kl_usb_probe+0x1233/0x1320 drivers/net/wireless/ath/ath6kl/usb.c:1168
 usb_probe_interface+0x5c0/0xaf0 drivers/usb/core/driver.c:396
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_set_configuration+0x19dd/0x2020 drivers/usb/core/message.c:2165
 usb_generic_driver_probe+0x84/0x140 drivers/usb/core/generic.c:238
 usb_probe_device+0x130/0x260 drivers/usb/core/driver.c:293
 really_probe+0x2ab/0xcb0 drivers/base/dd.c:639
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:785
 driver_probe_device+0x50/0x420 drivers/base/dd.c:815
 __device_attach_driver+0x2cf/0x510 drivers/base/dd.c:943
 bus_for_each_drv+0x183/0x200 drivers/base/bus.c:429
 __device_attach+0x359/0x570 drivers/base/dd.c:1015
 bus_probe_device+0xba/0x1e0 drivers/base/bus.c:489
 device_add+0xb48/0xfd0 drivers/base/core.c:3696
 usb_new_device+0xbdd/0x18f0 drivers/usb/core/hub.c:2620
 hub_port_connect drivers/usb/core/hub.c:5477 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5617 [inline]
 port_event drivers/usb/core/hub.c:5773 [inline]
 hub_event+0x2efe/0x5730 drivers/usb/core/hub.c:5855
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 process_scheduled_works kernel/workqueue.c:2355 [inline]
 worker_thread+0xd04/0x1200 kernel/workqueue.c:2441
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/06 12:48 linux-6.1.y 7dc732d24ff7 f3558dbf .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2024/11/25 18:20 linux-6.1.y e4d90d63d385 68da6d95 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2023/04/01 04:49 linux-6.1.y 3b29299e5f60 f325deb0 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2023/10/24 08:57 linux-6.1.y 7d24402875c7 af8d2e46 .config console log report syz [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: task hung in synchronize_rcu
2024/04/28 20:20 linux-6.1.y f2295faba5e8 07b455f9 .config console log report syz [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 INFO: task hung in synchronize_rcu
2025/01/27 01:52 linux-6.1.y 75cefdf153f5 9fbd772e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2025/01/21 22:34 linux-6.1.y f4f677285b38 da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2024/12/04 04:20 linux-6.1.y e4d90d63d385 b50eb251 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2024/10/19 11:59 linux-6.1.y 54d90d17e8ce cd6fc0a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2024/09/08 06:39 linux-6.1.y 699506173494 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2024/07/10 10:00 linux-6.1.y 7753af06eebf bc144f9a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2024/03/29 03:30 linux-6.1.y e5cd595e23c1 e91187ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2024/03/11 02:27 linux-6.1.y 61adba85cc40 6ee49f2e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
2023/11/04 16:01 linux-6.1.y 4a61839152cc 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: task hung in synchronize_rcu
* Struck through repros no longer work on HEAD.