INFO: task udevd:23401 blocked for more than 143 seconds. Not tainted 6.12.0-rc6-syzkaller-00153-g237d4e0f4113 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24272 pid:23401 tgid:23401 ppid:2864 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x1042/0x34b0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6782 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 device_lock include/linux/device.h:1014 [inline] uevent_show+0x188/0x3b0 drivers/base/core.c:2736 dev_attr_show+0x53/0xe0 drivers/base/core.c:2430 sysfs_kf_seq_show+0x23e/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4f4/0x12b0 fs/seq_file.c:230 kernfs_fop_read_iter+0x414/0x580 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:488 [inline] vfs_read+0x87f/0xbe0 fs/read_write.c:569 ksys_read+0x12f/0x260 fs/read_write.c:712 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbff2943b6a RSP: 002b:00007fffc0f11b88 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055fad1dbad90 RCX: 00007fbff2943b6a RDX: 0000000000001000 RSI: 000055fad1e56b60 RDI: 0000000000000008 RBP: 000055fad1dbad90 R08: 0000000000000008 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007fffc0f12068 R15: 000000000000000a Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2} , at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] , at: rcu_read_lock include/linux/rcupdate.h:849 [inline] , at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 5 locks held by kworker/0:2/704: 2 locks held by getty/2922: #0: ffff88810aafe0a0 (&tty->ldisc_sem){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 6 locks held by kworker/0:3/5269: #0: ffff8881062cb548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000246fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810af31190 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff8881f582c7d8 (hrtimer_bases.lock ){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:598 [inline] ){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1505 [inline] ){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1804 [inline] ){-.-.}-{2:2}, at: __schedule+0x293/0x34b0 kernel/sched/core.c:6589 #4: ffffffff88eed808 (tk_core.seq.seqcount){----}-{0:0} , at: timekeeping_get_ns kernel/time/timekeeping.c:401 [inline] , at: ktime_get+0xd9/0x1a0 kernel/time/timekeeping.c:850 #5: ffffffff935d46e8 (&obj_hash[i].lock ){-.-.}-{2:2}, at: debug_object_activate+0x199/0x540 lib/debugobjects.c:708 2 locks held by kworker/0:4/16027: #0: ffff888100080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90001c0fd80 (console_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 6 locks held by kworker/1:0/16127: 3 locks held by kworker/1:3/19680: 4 locks held by udevd/23160: #0: ffff88811be78418 (&p->lock){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888139fbac88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811492f0f8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881180dd190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff8881180dd190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 4 locks held by udevd/23167: #0: ffff88811be78540 (&p->lock ){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888139fba888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810f6a2968 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881180de190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff8881180de190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 4 locks held by udevd/23175: #0: ffff88812077d1c8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888133444888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811ca1e878 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888117c8b190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff888117c8b190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 4 locks held by udevd/23401: #0: ffff888122f941c8 ( &p->lock ){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88811dfa4088 (&of->mutex #2 ){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88812da691e8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88812a963190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff88812a963190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 6 locks held by kworker/0:6/23562: #0: ffff8881062cb548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900044cfd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810b36c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff88810b36c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff8881180de190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff8881180de190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888133973160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff888133973160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff8a0dcdc8 (register_mutex#3){+.+.}-{3:3}, at: usb_audio_probe+0x374/0x3c50 sound/usb/card.c:813 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00153-g237d4e0f4113 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 23562 Comm: kworker/0:6 Not tainted 6.12.0-rc6-syzkaller-00153-g237d4e0f4113 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: usb_hub_wq hub_event RIP: 0010:hlock_class+0x1d/0x130 kernel/locking/lockdep.c:223 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 53 48 89 fb 48 83 c7 20 48 89 fa 48 c1 ea 03 0f b6 04 02 <84> c0 74 08 3c 03 0f 8e da 00 00 00 0f b7 5b 20 66 81 e3 ff 1f 0f RSP: 0018:ffffc900044cf350 EFLAGS: 00000806 RAX: 0000000000000000 RBX: ffff888129420b10 RCX: 0000000000000002 RDX: 1ffff11025284166 RSI: ffff888129420b10 RDI: ffff888129420b30 RBP: ffffc900044cf4a0 R08: 0000000000000000 R09: fffffbfff1f559b4 R10: ffffffff8faacda7 R11: 0000000000000000 R12: ffff888129420000 R13: 0000000000000004 R14: 0000000000000002 R15: 1ffff92000899e72 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fad92545290 CR3: 00000001193ca000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_lock+0xb5/0xc60 kernel/locking/lockdep.c:4703 mark_usage kernel/locking/lockdep.c:4634 [inline] __lock_acquire+0x8a3/0x3ce0 kernel/locking/lockdep.c:5156 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 console_trylock_spinning kernel/printk/printk.c:2042 [inline] vprintk_emit+0x64c/0x6f0 kernel/printk/printk.c:2406 dev_vprintk_emit drivers/base/core.c:4942 [inline] dev_printk_emit+0xfb/0x140 drivers/base/core.c:4953 __dev_printk+0xf5/0x270 drivers/base/core.c:4965 _dev_info+0xe5/0x120 drivers/base/core.c:5011 usb_disconnect+0xec/0x920 drivers/usb/core/hub.c:2286 hub_port_connect drivers/usb/core/hub.c:5361 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5903 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244