INFO: task kworker/0:8:11931 blocked for more than 143 seconds. Not tainted 6.13.0-syzkaller-09485-g72deda0abee6 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:8 state:D stack:22600 pid:11931 tgid:11931 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x113d/0x35d0 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6856 schedule_timeout+0x244/0x280 kernel/time/sleep_timeout.c:75 ___down_common+0x2d7/0x460 kernel/locking/semaphore.c:225 __down_common kernel/locking/semaphore.c:246 [inline] __down+0x20/0x30 kernel/locking/semaphore.c:254 down+0x74/0xa0 kernel/locking/semaphore.c:63 console_lock+0x5b/0xa0 kernel/printk/printk.c:2833 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:3120 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 5 locks held by kworker/0:0/8: #0: ffff888106ea0548 ( (wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc9000008fd18 ((work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffff88810b3b3190 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5851 #3: ffff8881351f7190 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888119e3a160 ( &dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 6 locks held by kworker/1:0/24: #0: ffff888106ea0548 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc9000019fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffff88810b374190 (&dev->mutex ){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] ){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5851 #3: ffff888120d05190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #3: ffff888120d05190 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff8881062ff160 ( &dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] &dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffff888130321a20 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 1 lock held by khungtaskd/30: #0: ffffffff88ebe380 ( rcu_read_lock){....}-{1:3} , 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:6746 2 locks held by getty/2901: #0: ffff8881121370a0 (&tty->ldisc_sem){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 4 locks held by udevd/5253: #0: ffff888113d3d540 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888112110c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811ccc0878 (kn->active#5){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881351f7190 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729 4 locks held by udevd/5304: #0: ffff8881390571c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88810bbb3c88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810cf3aa58 (kn->active #5){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888120d05190 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1030 [inline] , at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729 2 locks held by kworker/0:8/11931: #0: ffff888100080d48 ((wq_completion)events ){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc90013a07d18 ( console_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 1 lock held by syz.2.2999/15205: 1 lock held by syz-executor/15211: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-syzkaller-09485-g72deda0abee6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 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: 2790 Comm: kworker/0:2 Not tainted 6.13.0-syzkaller-09485-g72deda0abee6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410 Code: 61 b2 fe 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 c8 6f 0c ff eb a2 e8 51 70 RSP: 0018:ffffc900049ff720 EFLAGS: 00000002 RAX: dffffc0000000060 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: ffffffff82c8c550 RDI: ffffffff936692e0 RBP: ffffffff936692a0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000 R13: 0000000000000020 R14: fffffbfff26cd2ae R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f78cfd87bac CR3: 00000001164e4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x137/0x210 drivers/tty/serial/8250/8250_port.c:2100 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0xf6c/0x1870 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3122 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3309 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2432 _printk+0xc8/0x100 kernel/printk/printk.c:2457 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_core_query+0x2d7/0x500 drivers/media/usb/dvb-usb/m920x.c:229 dvb_usb_read_remote_control+0xda/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244