INFO: task udevd:4251 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:udevd state:D stack:22600 pid:4251 ppid:3622 flags:0x00004002 Call Trace: 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 device_lock include/linux/device.h:837 [inline] uevent_show+0x176/0x330 drivers/base/core.c:2668 dev_attr_show+0x50/0xb0 drivers/base/core.c:2371 sysfs_kf_seq_show+0x32d/0x4b0 fs/sysfs/file.c:59 seq_read_iter+0x43a/0xd10 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+0x88d/0xbf0 fs/read_write.c:470 ksys_read+0x19c/0x2c0 fs/read_write.c:613 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7faaf3516b6a RSP: 002b:00007ffea6a72728 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055f3586b5570 RCX: 00007faaf3516b6a RDX: 0000000000001000 RSI: 000055f3586afcc0 RDI: 0000000000000008 RBP: 000055f3586b5570 R08: 0000000000000008 R09: 0000000000000020 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffea6a72c08 R15: 000000000000000a 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 1 lock held by khungtaskd/28: #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 2 locks held by getty/4005: #0: ffff88814ce3c098 (&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 4 locks held by udevd/4251: #0: ffff88801ffff418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xae/0xd10 fs/seq_file.c:182 #1: ffff888027971488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x4f/0x3a0 fs/kernfs/file.c:154 #2: ffff888058299830 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0x6e/0x3a0 fs/kernfs/file.c:155 #3: ffff88801ff86190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #3: ffff88801ff86190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x176/0x330 drivers/base/core.c:2668 4 locks held by kworker/u4:11/4377: #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545 #1: ffff8880b8e27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x419/0x790 kernel/sched/psi.c:999 #2: ffff8880b8e28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #3: ffffffff8d32b0c0 (rcu_read_lock){....}-{1:2}, at: ieee80211_sta_active_ibss+0xb1/0x310 net/mac80211/ibss.c:654 6 locks held by kworker/0:13/4740: #0: ffff888143293138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9001cf37d20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffff8880283d0190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #2: ffff8880283d0190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5730 drivers/usb/core/hub.c:5801 #3: ffff88801ff86190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #3: ffff88801ff86190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990 #4: ffff8880529bf118 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #4: ffff8880529bf118 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8a/0x570 drivers/base/dd.c:990 #5: ffffffff8d1d81b0 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0x13b/0x2f0 kernel/umh.c:218 3 locks held by kworker/u4:17/5207: #0: ffff8880b8e3a9d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545 #1: ffff8880b8e27788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x383/0x790 kernel/sched/psi.c:987 #2: ffff888059ff0d40 (&wdev->mtx){+.+.}-{3:3}, at: sdata_lock net/mac80211/ieee80211_i.h:1113 [inline] #2: ffff888059ff0d40 (&wdev->mtx){+.+.}-{3:3}, at: ieee80211_ibss_work+0xa0/0x1480 net/mac80211/ibss.c:1680 3 locks held by kworker/u4:25/5223: #0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90003667d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffffffff8d330580 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5f0 kernel/rcu/tree.c:4019 3 locks held by kworker/u4:28/5229: 1 lock held by sed/8663: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 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: __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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5209 Comm: kworker/u4:18 Not tainted 6.1.123-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024