INFO: task udevd:14672 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:23808 pid:14672 tgid:14672 ppid:2866 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: 0033:0x7efc54482b6a RSP: 002b:00007ffdcc94d8e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000555cdb7c12d0 RCX: 00007efc54482b6a RDX: 0000000000001000 RSI: 0000555cdb7dad10 RDI: 0000000000000008 RBP: 0000555cdb7c12d0 R08: 0000000000000008 R09: 0000000000000008 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffdcc94ddc8 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] ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 6 locks held by kworker/0:2/735: 2 locks held by getty/2924: #0: ffff88811211a0a0 (&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 5 locks held by kworker/0:4/5249: 4 locks held by kworker/1:4/5263: #0: ffff8881062cb548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000270fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810b362190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff88810b362190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88810b365508 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #3: ffff88810b365508 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x5c4/0x4f40 drivers/usb/core/hub.c:5902 5 locks held by kworker/1:5/5291: 4 locks held by udevd/14617: #0: ffff88811b2940a0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88811accfc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811fa32d28 (kn->active){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888105b8f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff888105b8f190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 4 locks held by udevd/14672: #0: ffff8881179e1d58 (&p->lock){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88811318d488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810dbc6968 (kn->active){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881326a2190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff8881326a2190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 6 locks held by kworker/0:5/17516: ============================================= NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11629 Comm: kworker/1:7 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: events dvb_usb_read_remote_control RIP: 0010:__lock_acquire+0x20e/0x3ce0 kernel/locking/lockdep.c:5108 Code: 03 48 89 34 24 48 0f af d1 48 89 54 24 20 8b 54 24 08 4c 8d 14 92 85 d2 4e 8d 2c d5 00 00 00 00 74 54 f6 84 24 48 01 00 00 01 <75> 4a 4e 8d 74 2e d8 48 ba 00 00 00 00 00 fc ff df 49 8d 7e 20 48 RSP: 0018:ffffc900001b89e0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 8f5c28f5c28f5c29 RDX: 0000000000000003 RSI: ffff88811a390a98 RDI: ffffffff88ebb148 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: 000000000000000f R11: 0000000000000002 R12: ffffffff88ebb140 R13: 0000000000000078 R14: 0000000000000000 R15: ffff88811a390000 FS: 0000000000000000(0000) GS:ffff8881f5900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555924594a8 CR3: 0000000114910000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] select_task_rq_fair+0x359/0x3ee0 kernel/sched/fair.c:8620 select_task_rq kernel/sched/core.c:3531 [inline] try_to_wake_up+0x3e6/0x1170 kernel/sched/core.c:4266 hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:1927 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x8b/0xb0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2042 [inline] RIP: 0010:vprintk_emit+0x621/0x6f0 kernel/printk/printk.c:2406 Code: 85 ed 0f 85 81 00 00 00 e8 0c 94 1f 00 9c 41 5c 41 81 e4 00 02 00 00 31 ff 4c 89 e6 e8 68 96 1f 00 4d 85 e4 0f 85 8d 00 00 00 ea 93 1f 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc9000273fb10 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 000000000000003e RCX: ffffffff81365f9e RDX: ffff88811a390000 RSI: ffffffff81365fa8 RDI: 0000000000000007 RBP: 1ffff920004e7f64 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000200 R14: ffff8881022b1d40 R15: ffffc9000273fbf8 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 dvb_usb_read_remote_control+0x174/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:263 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