INFO: task rcu_tasks_trace:13 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:rcu_tasks_trace state:D stack:28272 pid:13 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline] synchronize_rcu_expedited+0x7ad/0x890 kernel/rcu/tree_exp.h:962 synchronize_rcu+0x128/0x3f0 kernel/rcu/tree.c:3580 rcu_tasks_wait_gp+0x47c/0xab0 kernel/rcu/tasks.h:693 rcu_tasks_one_gp+0xd3f/0xf00 kernel/rcu/tasks.h:534 rcu_tasks_kthread+0x6e/0x90 kernel/rcu/tasks.h:562 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/1:0:22 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:22480 pid:22 ppid:2 flags:0x00004000 Workqueue: events pwq_unbound_release_workfn Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline] synchronize_rcu_expedited+0x7ad/0x890 kernel/rcu/tree_exp.h:962 synchronize_rcu+0x128/0x3f0 kernel/rcu/tree.c:3580 lockdep_unregister_key+0x4d2/0x550 kernel/locking/lockdep.c:6374 wq_unregister_lockdep kernel/workqueue.c:3500 [inline] pwq_unbound_release_workfn+0x262/0x2b0 kernel/workqueue.c:3738 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/1:2:951 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:20464 pid:951 ppid:2 flags:0x00004000 Workqueue: events pwq_unbound_release_workfn Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline] synchronize_rcu_expedited+0x7ad/0x890 kernel/rcu/tree_exp.h:962 synchronize_rcu+0x128/0x3f0 kernel/rcu/tree.c:3580 lockdep_unregister_key+0x4d2/0x550 kernel/locking/lockdep.c:6374 wq_unregister_lockdep kernel/workqueue.c:3500 [inline] pwq_unbound_release_workfn+0x262/0x2b0 kernel/workqueue.c:3738 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/1:3:4260 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:19416 pid:4260 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747 usb_audio_probe+0x3ac/0x1d90 sound/usb/card.c:812 usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2aa/0xc70 drivers/base/dd.c:639 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:785 driver_probe_device+0x4f/0x420 drivers/base/dd.c:815 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:1015 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3697 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+0x2aa/0xc70 drivers/base/dd.c:639 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:785 driver_probe_device+0x4f/0x420 drivers/base/dd.c:815 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:1015 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3697 usb_new_device+0xd66/0x1650 drivers/usb/core/hub.c:2659 hub_port_connect drivers/usb/core/hub.c:5517 [inline] hub_port_connect_change drivers/usb/core/hub.c:5657 [inline] port_event drivers/usb/core/hub.c:5817 [inline] hub_event+0x2dcf/0x5560 drivers/usb/core/hub.c:5899 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task kworker/1:4:4277 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:20976 pid:4277 ppid:2 flags:0x00004000 Workqueue: events pwq_unbound_release_workfn Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline] synchronize_rcu_expedited+0x7ad/0x890 kernel/rcu/tree_exp.h:962 synchronize_rcu+0x128/0x3f0 kernel/rcu/tree.c:3580 lockdep_unregister_key+0x4d2/0x550 kernel/locking/lockdep.c:6374 wq_unregister_lockdep kernel/workqueue.c:3500 [inline] pwq_unbound_release_workfn+0x262/0x2b0 kernel/workqueue.c:3738 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task udevd:4355 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:22928 pid:4355 ppid:3638 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747 device_lock include/linux/device.h:840 [inline] uevent_show+0x16c/0x320 drivers/base/core.c:2669 dev_attr_show+0x50/0xb0 drivers/base/core.c:2372 sysfs_kf_seq_show+0x349/0x4b0 fs/sysfs/file.c:59 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x4a7/0xa00 fs/read_write.c:470 ksys_read+0x14c/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa3b78a7407 RSP: 002b:00007ffd58b25c80 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fa3b7f8b880 RCX: 00007fa3b78a7407 RDX: 0000000000001000 RSI: 00005640e61c3280 RDI: 0000000000000008 RBP: 00007fa3b79efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007fa3b79efea0 R14: 0000000000000000 R15: 00005640e61487a0 INFO: task kworker/u4:11:4400 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:11 state:D stack:23536 pid:4400 ppid:2 flags:0x00004000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline] synchronize_rcu_expedited+0x7ad/0x890 kernel/rcu/tree_exp.h:962 dev_deactivate_many+0x635/0xcb0 net/sched/sch_generic.c:1346 dev_deactivate+0x114/0x1b0 net/sched/sch_generic.c:1372 linkwatch_do_dev+0x105/0x160 net/core/link_watch.c:166 __linkwatch_run_queue+0x410/0x660 net/core/link_watch.c:221 linkwatch_event+0x48/0x50 net/core/link_watch.c:264 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task udevd:4543 blocked for more than 147 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24432 pid:4543 ppid:3638 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x562/0xaf0 kernel/locking/mutex.c:747 device_lock include/linux/device.h:840 [inline] uevent_show+0x16c/0x320 drivers/base/core.c:2669 dev_attr_show+0x50/0xb0 drivers/base/core.c:2372 sysfs_kf_seq_show+0x349/0x4b0 fs/sysfs/file.c:59 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x4a7/0xa00 fs/read_write.c:470 ksys_read+0x14c/0x250 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa3b78a7407 RSP: 002b:00007ffd58b25c80 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fa3b7f8b880 RCX: 00007fa3b78a7407 RDX: 0000000000001000 RSI: 00005640e61c3280 RDI: 0000000000000008 RBP: 00007fa3b79efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007fa3b79efea0 R14: 0000000000000000 R15: 00005640e61487a0 INFO: task syz-executor:6926 blocked for more than 147 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21584 pid:6926 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline] synchronize_rcu_expedited+0x7ad/0x890 kernel/rcu/tree_exp.h:962 namespace_unlock+0x23f/0x430 fs/namespace.c:1502 do_umount fs/namespace.c:1726 [inline] path_umount+0xf19/0xf90 fs/namespace.c:1809 ksys_umount fs/namespace.c:1832 [inline] __do_sys_umount fs/namespace.c:1837 [inline] __se_sys_umount fs/namespace.c:1835 [inline] __x64_sys_umount+0x12d/0x170 fs/namespace.c:1835 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f36cf39e097 RSP: 002b:00007fffa64d1a78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 00007f36cf4321ca RCX: 00007f36cf39e097 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffa64d1b30 RBP: 00007fffa64d1b30 R08: 00007fffa64d2b30 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffa64d2bc0 R13: 00007f36cf4321ca R14: 000000000009a692 R15: 00007fffa64d2c00 INFO: task kworker/u4:7:10720 blocked for more than 148 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:7 state:D stack:23952 pid:10720 ppid:2 flags:0x00004000 Workqueue: events_unbound bpf_map_free_deferred Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 exp_funnel_lock kernel/rcu/tree_exp.h:314 [inline] synchronize_rcu_expedited+0x7ad/0x890 kernel/rcu/tree_exp.h:962 synchronize_rcu+0x128/0x3f0 kernel/rcu/tree.c:3580 sock_hash_free+0x89/0x7d0 net/core/sock_map.c:1146 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2df70 ( rcu_tasks.tasks_gp_mutex ){+.+.}-{3:3} , at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2e790 ( rcu_tasks_trace.tasks_gp_mutex ){+.+.}-{3:3} , at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 2 locks held by kworker/1:0/22: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc900001c7d00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 1 lock held by khungtaskd/27: #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 5 locks held by kworker/u4:3/46: 2 locks held by kworker/1:2/951: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc9000448fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 2 locks held by getty/4027: #0: ffff88802fb3b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198 6 locks held by kworker/1:3/4260: #0: ffff888144ea2138 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc90003c27d00 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffff888027bf8190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:840 [inline] , at: hub_event+0x19f/0x5560 drivers/usb/core/hub.c:5845 #3: ffff888054a6e190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:840 [inline] , at: __device_attach+0x85/0x480 drivers/base/dd.c:990 #4: ffff888027a44118 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:840 [inline] , at: __device_attach+0x85/0x480 drivers/base/dd.c:990 #5: ffffffff8dcecc48 ( register_mutex#6){+.+.}-{3:3}, at: usb_audio_probe+0x3ac/0x1d90 sound/usb/card.c:812 2 locks held by kworker/1:4/4277: #0: ffff888017470938 ( (wq_completion)events ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc90003e57d00 ( (work_completion)(&pwq->unbound_release_work) ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 9 locks held by kworker/0:3/4315: 4 locks held by udevd/4355: #0: ffff8880730269e0 ( &p->lock ){+.+.}-{3:3} , at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff888055b4a888 ( &of->mutex ){+.+.}-{3:3} , at: kernfs_seq_start+0x58/0x410 fs/kernfs/file.c:172 #2: ffff888079f1c3a8 ( kn->active #5){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #5){.+.+}-{0:0}, at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173 #3: ffff8880682a7190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:840 [inline] , at: uevent_show+0x16c/0x320 drivers/base/core.c:2669 3 locks held by kworker/u4:11/4400: #0: ffff888017479138 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc90004717d00 ( (linkwatch_work).work ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 4 locks held by udevd/4543: #0: ffff888020996b08 ( &p->lock ){+.+.}-{3:3} , at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff88807c4b3488 ( &of->mutex ){+.+.}-{3:3} , at: kernfs_seq_start+0x58/0x410 fs/kernfs/file.c:172 #2: ffff8880583aa008 ( kn->active #5 ){.+.+}-{0:0} , at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] , at: kernfs_seq_start+0xae/0x410 fs/kernfs/file.c:173 #3: ffff888054a6e190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:840 [inline] , at: uevent_show+0x16c/0x320 drivers/base/core.c:2669 2 locks held by kworker/u4:7/10720: #0: ffff888017479138 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc9000d097d00 ( (work_completion)(&map->work) ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 2 locks held by kworker/u4:18/10726: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc9000d147d00 ( (reaper_work).work ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 2 locks held by kworker/u4:20/10732: #0: ffff888017479138 ( (wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc9000c747d00 ( connector_reaper_work ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 4 locks held by kvm-nx-lpage-re/11732: #0: ffffffff8cb56068 ( cgroup_mutex ){+.+.}-{3:3} , at: cgroup_lock include/linux/cgroup.h:442 [inline] , at: cgroup_attach_task_all+0x22/0xe0 kernel/cgroup/cgroup-v1.c:61 #1: ffffffff8c9c9eb0 ( cpu_hotplug_lock ){++++}-{0:0} , at: cgroup_attach_lock+0xd/0x30 kernel/cgroup/cgroup.c:2476 #2: ffffffff8cb56250 ( cgroup_threadgroup_rwsem ){++++}-{0:0} , at: cgroup_attach_task_all+0x2c/0xe0 kernel/cgroup/cgroup-v1.c:62 #3: ffffffff8cb332b8 ( rcu_state.exp_mutex ){+.+.}-{3:3} , at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] , at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962 2 locks held by syz.0.2123/11738: #0: ffff888147268eb8 ( &nft_net->commit_mutex ){+.+.}-{3:3} , at: nf_tables_valid_genid+0x37/0x100 net/netfilter/nf_tables_api.c:10232 #1: ffffffff8cb332b8 ( rcu_state.exp_mutex ){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] ){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962 1 lock held by dhcpcd/11749: #0: ffff8880754f0130 ( sk_lock-AF_PACKET ){+.+.}-{0:0} , at: lock_sock include/net/sock.h:1805 [inline] , at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by dhcpcd/11765: #0: ffff888051f54130 ( sk_lock-AF_PACKET ){+.+.}-{0:0} , at: lock_sock include/net/sock.h:1805 [inline] , at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by syz.4.2139/11779: #0: ffff888054536810 ( &sb->s_type->i_mutex_key #11 ){+.+.}-{3:3} , at: inode_lock include/linux/fs.h:758 [inline] , at: __sock_release net/socket.c:653 [inline] , at: sock_close+0x90/0x240 net/socket.c:1399 1 lock held by dhcpcd/11782: #0: ffff888023f96130 ( sk_lock-AF_PACKET ){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] ){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by syz-executor/11784: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11793: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 3 locks held by kworker/1:7/11794: #0: ffff88814d049138 ( (wq_completion)ipv6_addrconf ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #1: ffffc90005e0fd00 ( (work_completion)(&(&net->ipv6.addr_chk_work)->work) ){+.+.}-{0:0} , at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4672 1 lock held by syz-executor/11797: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11799: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by dhcpcd/11801: #0: ffff88805828c130 ( sk_lock-AF_PACKET ){+.+.}-{0:0} , at: lock_sock include/net/sock.h:1805 [inline] , at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by dhcpcd/11802: #0: ffff888028f9e130 ( sk_lock-AF_PACKET ){+.+.}-{0:0} , at: lock_sock include/net/sock.h:1805 [inline] , at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by dhcpcd/11803: #0: ffff88802ed7a130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff88802ed7a130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by syz-executor/11805: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by dhcpcd/11807: #0: ffff88802abf6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline] #0: ffff88802abf6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by syz-executor/11809: #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11812: #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11816: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11818: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11823: #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11826: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11829: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11833: #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11835: #0: ffffffff8dd47f28 ( rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 1 lock held by syz-executor/11838: #0: ffffffff8dd47f28 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x824/0xfc0 net/core/rtnetlink.c:6154 ============================================= 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: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4315 Comm: kworker/0:3 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:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: e8 32 dc ff fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 53 e8 50 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c RSP: 0018:ffffc90004445f98 EFLAGS: 00000002 RAX: 1ffffffff2df0e00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 00000000000fffff RDI: 0000000000100000 RBP: ffffc90004446190 R08: ffff888023df0237 R09: 1ffff110047be046 R10: dffffc0000000000 R11: ffffed10047be047 R12: dffffc0000000000 R13: 0000000000002703 R14: ffffffff96f87520 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f44bd69c2c8 CR3: 000000007f7be000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:117 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:139 [inline] wait_for_lsr drivers/tty/serial/8250/8250_port.c:2101 [inline] fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3372 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3394 [inline] serial8250_console_write+0xf74/0x17f0 drivers/tty/serial/8250/8250_port.c:3479 call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0x79e/0xba0 kernel/printk/printk.c:2777 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303 dev_vprintk_emit+0x34e/0x400 drivers/base/core.c:4933