INFO: task kworker/0:4:5233 blocked for more than 143 seconds. Not tainted 6.13.0-rc7-syzkaller-g70cd0576aa39 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:20368 pid:5233 tgid:5233 ppid:2 flags:0x00004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x102c/0x34b0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 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+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 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff88ebc880 ( rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6744 2 locks held by getty/2908: #0: ffff8881152500a0 (&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/5227: #0: ffff888114e240a0 (&p->lock ){+.+.}-{4:4}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88811ad82c88 (&of->mutex#2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88813a719878 (kn->active#4){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88813c1c2190 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1014 [inline] , at: uevent_show+0x188/0x3b0 drivers/base/core.c:2729 2 locks held by kworker/0:4/5233: #0: ffff888100080948 ((wq_completion)events ){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc9000212fd80 (console_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 6 locks held by kworker/1:3/5236: 4 locks held by kworker/0:10/15084: 3 locks held by kworker/0:7/20597: 5 locks held by kworker/0:11/20893: #0: ffff888106687548 ((wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3211 #1: ffffc900074efd80 ((work_completion)(&hub->events) ){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3212 #2: ffff88810af1e190 (&dev->mutex ){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] ){....}-{4:4}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5851 #3: ffff88813c1c2190 (&dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888100f2e160 ( &dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] &dev->mutex){....}-{4:4}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc7-syzkaller-g70cd0576aa39 #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:234 [inline] watchdog+0xf14/0x1240 kernel/hung_task.c:397 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: 11696 Comm: kworker/0:8 Not tainted 6.13.0-rc7-syzkaller-g70cd0576aa39 #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:write_comp_data+0x42/0x90 kernel/kcov.c:246 Code: a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 54 15 00 00 85 c0 74 4f 8b 82 30 15 00 00 <83> f8 03 75 44 48 8b 82 38 15 00 00 8b 92 34 15 00 00 48 8b 38 48 RSP: 0018:ffffc90001d7f738 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff93477620 RCX: ffffffff82aa97d2 RDX: ffff88810c2aba80 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffffffff893a96c0 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000006 R12: 0000000000000000 R13: ffffffff936448e0 R14: ffffffff93644a20 R15: 000000000000002f FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002200 CR3: 0000000117e5c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __uart_port_using_nbcon include/linux/serial_core.h:651 [inline] __uart_port_nbcon_acquire include/linux/serial_core.h:672 [inline] uart_port_lock_irqsave include/linux/serial_core.h:716 [inline] serial8250_console_write+0xcd2/0x17c0 drivers/tty/serial/8250/8250_port.c:3372 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 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:86 _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+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