syzbot


INFO: task hung in linkwatch_event (3)

Status: upstream: reported on 2025/09/20 20:03
Reported-by: syzbot+42d5561bdaee9b3a7582@syzkaller.appspotmail.com
First crash: 223d, last: 4d06h
Similar bugs (20)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: task hung in linkwatch_event (2) 1 1 447d 447d 0/3 auto-obsoleted due to no activity on 2025/05/19 15:08
linux-6.1 INFO: task hung in linkwatch_event (5) 1 syz error 8 16d 188d 0/3 upstream: reported syz repro on 2025/10/25 05:38
linux-6.1 INFO: task hung in linkwatch_event (4) 1 syz 7 323d 414d 0/3 auto-obsoleted due to no activity on 2025/09/20 14:43
android-414 INFO: task hung in linkwatch_event 1 C 7 2358d 2578d 0/1 public: reported C repro on 2019/04/10 16:14
linux-6.6 INFO: task hung in linkwatch_event origin:lts-only 1 C inconclusive 19 13d 301d 0/2 upstream: reported C repro on 2025/07/04 13:16
linux-4.14 INFO: task hung in linkwatch_event (2) 1 1 1379d 1379d 0/1 auto-obsoleted due to no activity on 2022/11/19 11:58
android-44 INFO: task hung in linkwatch_event 1 6 2794d 2939d 0/2 auto-closed as invalid on 2019/03/05 13:11
linux-5.15 INFO: task hung in linkwatch_event 1 84 545d 841d 0/3 auto-obsoleted due to no activity on 2025/01/11 00:55
upstream INFO: task hung in linkwatch_event (4) net 1 C done 3529 23h53m 643d 0/29 upstream: reported C repro on 2024/07/27 06:21
upstream INFO: task hung in linkwatch_event net 1 C 82 2386d 2998d 0/29 closed as dup on 2018/02/14 15:33
linux-4.14 INFO: task hung in linkwatch_event 1 5 2062d 2189d 0/1 auto-closed as invalid on 2021/01/05 01:42
linux-4.19 INFO: task hung in linkwatch_event (2) 1 C error 217 1153d 2242d 0/1 upstream: reported C repro on 2020/03/11 20:12
upstream INFO: task hung in linkwatch_event (2) net 1 C done done 1033 1467d 2193d 20/29 fixed on 2022/05/13 11:13
linux-4.19 INFO: task hung in linkwatch_event 1 3 2395d 2509d 0/1 auto-closed as invalid on 2020/02/07 01:11
upstream INFO: task hung in linkwatch_event (3) net 1 1634 661d 1256d 26/29 fixed on 2024/07/09 19:14
linux-4.14 INFO: task hung in linkwatch_event (3) 1 2 1213d 1214d 0/1 upstream: reported on 2023/01/03 10:49
android-49 INFO: task hung in linkwatch_event 1 13 2557d 2574d 0/3 auto-closed as invalid on 2019/10/25 08:50
linux-6.1 INFO: task hung in linkwatch_event (2) 1 32 596d 711d 0/3 auto-obsoleted due to no activity on 2024/11/21 00:32
linux-6.1 INFO: task hung in linkwatch_event 1 2 999d 1115d 0/3 auto-obsoleted due to no activity on 2023/11/14 00:59
linux-6.1 INFO: task hung in linkwatch_event (3) 1 1 522d 522d 0/3 auto-obsoleted due to no activity on 2025/03/05 15:51

Sample crash report:
INFO: task kworker/u4:3:892 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:3    state:D
 stack:21264 pid:  892 ppid:     2 flags:0x00004000
Workqueue: events_unbound linkwatch_event

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 linkwatch_event+0xa/0x50 net/core/link_watch.c:251
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task syz-executor:4185 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D
 stack:21808 pid: 4185 ppid:     1 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 exp_funnel_lock kernel/rcu/tree_exp.h:313 [inline]
 synchronize_rcu_expedited+0x680/0x750 kernel/rcu/tree_exp.h:845
 namespace_unlock+0x23f/0x430 fs/namespace.c:1459
 drop_collected_mounts fs/namespace.c:1948 [inline]
 put_mnt_ns+0xdb/0x120 fs/namespace.c:4426
 free_nsproxy+0x49/0x3c0 kernel/nsproxy.c:191
 do_exit+0x621/0x20c0 kernel/exit.c:882
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 get_signal+0x6ca/0x12c0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f24ddf3360e
RSP: 002b:00007ffe87173a18 EFLAGS: 00000246 ORIG_RAX: 000000000000003d
RAX: fffffffffffffe00 RBX: 00005555797c4500 RCX: 00007f24ddf3360e
RDX: 0000000040000000 RSI: 00007ffe87173abc RDI: ffffffffffffffff
RBP: 00007ffe87173abc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000042
R13: 00005555797d79f0 R14: 0000000000029176 R15: 00007ffe87173b10
 </TASK>
INFO: task syz-executor:4190 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21968 pid: 4190 ppid:     1 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 exp_funnel_lock kernel/rcu/tree_exp.h:313 [inline]
 synchronize_rcu_expedited+0x680/0x750 kernel/rcu/tree_exp.h:845
 namespace_unlock+0x23f/0x430 fs/namespace.c:1459
 do_umount fs/namespace.c:1683 [inline]
 path_umount+0xf64/0xfd0 fs/namespace.c:1766
 ksys_umount fs/namespace.c:1789 [inline]
 __do_sys_umount fs/namespace.c:1794 [inline]
 __se_sys_umount fs/namespace.c:1792 [inline]
 __x64_sys_umount+0x12d/0x170 fs/namespace.c:1792
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9327932017
RSP: 002b:00007ffc62142ca8 EFLAGS: 00000246
 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f93279c6120 RCX: 00007f9327932017
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc62142d60
RBP: 00007ffc62142d60 R08: 00007ffc62143d60 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc62143df0
R13: 00007f93279c6120 R14: 000000000002aa96 R15: 00007ffc62143e30
 </TASK>
INFO: task kworker/u4:5:4265 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:5    state:D
 stack:24504 pid: 4265 ppid:     2 flags:0x00004000
Workqueue: events_unbound fsnotify_mark_destroy_workfn

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
 do_wait_for_common+0x2a2/0x450 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 __synchronize_srcu+0x2bb/0x350 kernel/rcu/srcutree.c:930
 fsnotify_mark_destroy_workfn+0x106/0x2f0 fs/notify/mark.c:924
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task kworker/u4:14:4418 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:14   state:D
 stack:25072 pid: 4418 ppid:     2 flags:0x00004000
Workqueue: events_unbound fsnotify_connector_destroy_workfn

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
 do_wait_for_common+0x2a2/0x450 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 __synchronize_srcu+0x2bb/0x350 kernel/rcu/srcutree.c:930
 fsnotify_connector_destroy_workfn+0x40/0xa0 fs/notify/mark.c:234
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task udevd:4452 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D
 stack:23536 pid: 4452 ppid:  3561 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 device_lock include/linux/device.h:764 [inline]
 uevent_show+0x17a/0x330 drivers/base/core.c:2408
 dev_attr_show+0x50/0xb0 drivers/base/core.c:2110
 sysfs_kf_seq_show+0x316/0x4c0 fs/sysfs/file.c:61
 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230
 call_read_iter include/linux/fs.h:2167 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x759/0xd60 fs/read_write.c:485
 ksys_read+0x152/0x260 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f95553a6407
RSP: 002b:00007ffc4eeea4f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f95552b8880 RCX: 00007f95553a6407
RDX: 0000000000001000 RSI: 000055e0b98d0a00 RDI: 0000000000000008
RBP: 00007f95554eeff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007f95554eeea0 R14: 0000000000000000 R15: 000055e0b98f1cc0
 </TASK>
INFO: task udevd:4457 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D
 stack:25040 pid: 4457 ppid:  3561 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 btrfs_control_ioctl+0xc0/0x220 fs/btrfs/super.c:2453
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f955541c378
RSP: 002b:00007ffc4eeecd78 EFLAGS: 00000246
 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f955541c378
RDX: 00007ffc4eeecd80 RSI: 0000000090009427 RDI: 0000000000000009
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc4eeecd80
R13: 000055e0b98d9a40 R14: 0000000000000009 R15: 00007ffc4eeedde0
 </TASK>
INFO: task udevd:5354 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D
 stack:25040 pid: 5354 ppid:  3561 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 btrfs_control_ioctl+0xc0/0x220 fs/btrfs/super.c:2453
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f955541c378
RSP: 002b:00007ffc4eeecd78 EFLAGS: 00000246
 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f955541c378
RDX: 00007ffc4eeecd80 RSI: 0000000090009427 RDI: 0000000000000009
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc4eeecd80
R13: 000055e0b98de2a0 R14: 0000000000000009 R15: 00007ffc4eeedde0
 </TASK>
INFO: task syz.0.325:5408 blocked for more than 147 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.325       state:D stack:26608 pid: 5408 ppid:  4185 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
 synchronize_rcu+0x119/0x1e0 kernel/rcu/tree.c:3802
 pep_sock_unhash+0x200/0x2e0 net/phonet/pep.c:1341
 sk_common_release+0xa0/0x310 net/core/sock.c:3472
 pep_sock_close+0x78/0x620 net/phonet/pep.c:740
 pn_socket_release+0x91/0xb0 net/phonet/socket.c:34
 __sock_release net/socket.c:651 [inline]
 sock_close+0xd5/0x240 net/socket.c:1345
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x626/0x20c0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 get_signal+0x6ca/0x12c0 kernel/signal.c:2900
 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f24ddf72dd9
RSP: 002b:00007f24dc1ab028 EFLAGS: 00000246
 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f24de1ec090 RCX: 00007f24ddf72dd9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f24de008d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f24de1ec128 R14: 00007f24de1ec090 R15: 00007ffe87173718
 </TASK>
INFO: task syz.4.331:5430 blocked for more than 148 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.331       state:D
 stack:25176 pid: 5430 ppid:  4193 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
 do_wait_for_common+0x2a2/0x450 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 __flush_work+0x15a/0x210 kernel/workqueue.c:3094
 __lru_add_drain_all+0x9ce/0xac0 mm/swap.c:833
 invalidate_bdev+0x8f/0xb0 block/bdev.c:87
 btrfs_get_bdev_and_sb+0x152/0x1e0 fs/btrfs/volumes.c:519
 btrfs_open_one_device fs/btrfs/volumes.c:656 [inline]
 open_fs_devices+0x1cc/0xd10 fs/btrfs/volumes.c:1307
 btrfs_mount_root+0x534/0x930 fs/btrfs/super.c:1725
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 fc_mount fs/namespace.c:1005 [inline]
 vfs_kern_mount+0xba/0x150 fs/namespace.c:1035
 btrfs_mount+0x342/0xb10 fs/btrfs/super.c:1811
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5c15f4504a
RSP: 002b:00007f5c1419ce58 EFLAGS: 00000246
 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5c1419cee0 RCX: 00007f5c15f4504a
RDX: 00002000000055c0 RSI: 00002000000001c0 RDI: 00007f5c1419cea0
RBP: 00002000000055c0 R08: 00007f5c1419cee0 R09: 000000000300000a
R10: 000000000300000a R11: 0000000000000246 R12: 00002000000001c0
R13: 00007f5c1419cea0 R14: 00000000000055a3 R15: 0000200000000540
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/u4:0/9:
 #0: 
ffff888016c79138
 (
(wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc90000ce7d00
 (
(work_completion)(&rdev->wiphy_work)
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: 
ffff8880287e0688
 (
&rdev->wiphy.mtx
){+.+.}-{3:3}
, at: wiphy_lock include/net/cfg80211.h:5319 [inline]
, at: cfg80211_wiphy_work+0x31/0x260 net/wireless/core.c:420
 #3: 
ffff88805f67cd40
 (
&wdev->mtx
){+.+.}-{3:3}
, at: sdata_lock net/mac80211/ieee80211_i.h:1036 [inline]
, at: ieee80211_ibss_work+0xa8/0x10e0 net/mac80211/ibss.c:1685
 #4: 
ffff8880287e1810
 (
&local->sta_mtx
){+.+.}-{3:3}
, at: ieee80211_ibss_sta_expire net/mac80211/ibss.c:1259 [inline]
, at: ieee80211_sta_merge_ibss net/mac80211/ibss.c:1302 [inline]
, at: ieee80211_ibss_work+0x571/0x10e0 net/mac80211/ibss.c:1713
1 lock held by khungtaskd/27:
 #0: 
ffffffff8c31eb20
 (
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:3/892:
 #0: 
ffff888016c79138
 (
(wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc9000422fd00
 (
(linkwatch_work).work
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: 
ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
3 locks held by kworker/1:2/1108:
 #0: ffff888016c70938
 (
(wq_completion)events
){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc9000488fd00
 (
deferred_process_work
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: 
ffffffff8d43d408
 (
rtnl_mutex
){+.+.}-{3:3}
, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:74
2 locks held by getty/3949:
 #0: 
ffff88814cc3d098
 (
&tty->ldisc_sem
){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
9 locks held by kworker/0:8/4262:
2 locks held by kworker/u4:5/4265:
 #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc900031efd00
 ((reaper_work).work
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
3 locks held by kworker/1:8/4308:
 #0: 
ffff88802b64f138
 (
(wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc9000335fd00
 (
(addr_chk_work).work
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
 #2: 
ffffffff8d43d408
 (
rtnl_mutex
){+.+.}-{3:3}
, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4654
2 locks held by kworker/u4:14/4418:
 #0: 
ffff888016c79138
 (
(wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
 #1: 
ffffc900033bfd00 (
connector_reaper_work
){+.+.}-{0:0}
, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
4 locks held by udevd/4452:
 #0: 
ffff888060995668
 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
 #1: ffff88807998c488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112
 #2: ffff88807901c748 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113
 #3: ffff88802b302220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #3: ffff88802b302220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408
1 lock held by udevd/4457:
 #0: ffffffff8c8089a8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_control_ioctl+0xc0/0x220 fs/btrfs/super.c:2453
1 lock held by udevd/5354:
 #0: 
ffffffff8c8089a8
 (uuid_mutex){+.+.}-{3:3}, at: btrfs_control_ioctl+0xc0/0x220 fs/btrfs/super.c:2453
3 locks held by syz.0.325/5408:
 #0: ffff88805f077410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #0: ffff88805f077410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline]
 #0: ffff88805f077410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345
 #1: ffff888079930120 (sk_lock-AF_PHONET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #1: ffff888079930120 (sk_lock-AF_PHONET){+.+.}-{0:0}, at: pep_sock_unhash+0x26/0x2e0 net/phonet/pep.c:1325
 #2: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #2: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
2 locks held by syz.4.331/5430:
 #0: ffffffff8c8089a8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_mount_root+0x271/0x930 fs/btrfs/super.c:1708
 #1: ffffffff8c3b44c8 (lock#4){+.+.}-{3:3}, at: __lru_add_drain_all+0x68/0xac0 mm/swap.c:782
1 lock held by syz.2.335/5438:
 #0: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.3.352/5498:
 #0: ffffffff8c8089a8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_mount_root+0x271/0x930 fs/btrfs/super.c:1708
1 lock held by syz-executor/5499:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5507:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5510:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5513:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5516:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by dhcpcd/5518:
 #0: ffff888027f94120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff888027f94120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213
1 lock held by dhcpcd/5519:
 #0: 
ffff888059436120 (
sk_lock-AF_PACKET
){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213
1 lock held by dhcpcd/5520:
 #0: ffff888075e28120 (sk_lock-AF_PACKET){+.+.}-{0:0}
, at: lock_sock include/net/sock.h:1744 [inline]
, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213
1 lock held by dhcpcd/5521:
 #0: ffff888059070120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff888059070120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213
1 lock held by dhcpcd/5522:
 #0: 
ffff8880712de120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
ffff8880712de120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213
1 lock held by dhcpcd/5523:
 #0: 
ffff8880593ac120 (
sk_lock-AF_PACKET
){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
){+.+.}-{0:0}, at: packet_do_bind+0x35/0xda0 net/packet/af_packet.c:3213
1 lock held by syz-executor/5525:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5528:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5531:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5534:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5537:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5540:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5543:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5546:
 #0: 
ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5549:
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d43d408 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684
1 lock held by syz-executor/5552:
 #0: ffffffff8d43d408 (rtnl_mutex
){+.+.}-{3:3}
, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
, at: rtnetlink_rcv_msg+0x7ee/0xf30 net/core/rtnetlink.c:5684

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4262 Comm: kworker/0:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: usb_hub_wq hub_event
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:ffffc900031be1d8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 1ffff92000637c40 RCX: 0000000000000000
RDX: 000000000000000c RSI: 0000000000000000 RDI: ffffc900031be22c
RBP: ffffc900031be290 R08: 0000000000000003 R09: ffffc900031be220
R10: dffffc0000000000 R11: fffff52000637c45 R12: 000000000000001b
R13: ffffc900031be220 R14: ffffc900031be32e R15: ffffc900031be320
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556f27781000 CR3: 00000000187a6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 print_caller kernel/printk/printk.c:1281 [inline]
 info_print_prefix+0x1bf/0x360 kernel/printk/printk.c:1302
 record_print_text kernel/printk/printk.c:1349 [inline]
 console_unlock+0x66e/0x1120 kernel/printk/printk.c:2725
 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
 dev_vprintk_emit+0x2e1/0x380 drivers/base/core.c:4638
 dev_printk_emit+0xeb/0x140 drivers/base/core.c:4649
 _dev_err+0x11b/0x170 drivers/base/core.c:4704
 parse_uac2_sample_rate_range+0x992/0xc60 sound/usb/format.c:401
 parse_audio_format_rates_v2v3+0x3c7/0x16c0 sound/usb/format.c:636
 parse_audio_format_ii sound/usb/format.c:778 [inline]
 snd_usb_parse_audio_format+0x4ae/0x740 sound/usb/format.c:799
 snd_usb_get_audioformat_uac12 sound/usb/stream.c:854 [inline]
 __snd_usb_parse_audio_interface+0x18b1/0x4b00 sound/usb/stream.c:1196
 snd_usb_parse_audio_interface+0x36/0xb0 sound/usb/stream.c:1274
 create_standard_audio_quirk+0x59/0x120 sound/usb/quirks.c:100
 snd_usb_create_quirk sound/usb/quirks.c:577 [inline]
 create_composite_quirk+0x1ec/0x4e0 sound/usb/quirks.c:48
 usb_audio_probe+0xb97/0x1d90 sound/usb/card.c:885
 usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x284/0xc80 drivers/base/dd.c:595
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a8/0x480 drivers/base/dd.c:979
 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
 device_add+0xa00/0xfb0 drivers/base/core.c:3412
 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2223
 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x284/0xc80 drivers/base/dd.c:595
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a8/0x480 drivers/base/dd.c:979
 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
 device_add+0xa00/0xfb0 drivers/base/core.c:3412
 usb_new_device+0xd65/0x1660 drivers/usb/core/hub.c:2632
 hub_port_connect drivers/usb/core/hub.c:5497 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 port_event drivers/usb/core/hub.c:5799 [inline]
 hub_event+0x2e4a/0x55e0 drivers/usb/core/hub.c:5881
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/27 16:54 linux-5.15.y b9d57c40a767 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in linkwatch_event
2026/01/23 13:24 linux-5.15.y 9eec9a14ee10 e2b1b6e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: task hung in linkwatch_event
2025/12/29 18:30 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: task hung in linkwatch_event
2025/11/06 21:27 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: task hung in linkwatch_event
2025/10/13 19:56 linux-5.15.y 29e53a5b1c4f b6605ba8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in linkwatch_event
2025/09/20 20:03 linux-5.15.y 43bb85222e53 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: task hung in linkwatch_event
* Struck through repros no longer work on HEAD.