INFO: task kworker/1:9:17920 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/1:9 state:D stack:22768 pid:17920 tgid:17920 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events console_callback Call Trace: <TASK> 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 </TASK> Showing all locks held in the system: 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/2902: #0: ffff88811280d0a0 (&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 5 locks held by kworker/1:4/5236: 4 locks held by kworker/0:5/5402: 4 locks held by udevd/8393: #0: ffff88813101ce80 (&p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888103b33488 (&of->mutex ){+.+.}-{4:4}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff8881172011e8 (kn->active){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888113790190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline] #3: ffff888113790190 (&dev->mutex){....}-{4:4}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729 6 locks held by kworker/1:2/17781: 2 locks held by kworker/1:9/17920: #0: ffff888100080d48 ((wq_completion)events ){+.+.}-{0:0} , at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc9000edc7d18 (console_work ){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 6 locks held by kworker/1:11/23937: 1 lock held by syz.5.4612/25762: 2 locks held by syz.9.4615/25767: 1 lock held by dhcpcd-run-hook/25784: ============================================= 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: <TASK> __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 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 24442 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 legacy_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:ffffc9000e3176d8 EFLAGS: 00000006 RAX: dffffc0000000005 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff82c8c550 RDI: ffffffff936692e0 RBP: ffffffff936692a0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000 R13: ffffffff936692f0 R14: ffffffff936692a0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d0b8847300 CR3: 0000000117974000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> serial_port_in include/linux/serial_core.h:791 [inline] serial8250_console_write+0x237/0x1870 drivers/tty/serial/8250/8250_port.c:3420 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_query+0x496/0x770 drivers/media/usb/dvb-usb/m920x.c:193 legacy_dvb_usb_read_remote_control+0x10a/0x500 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 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 </TASK>