INFO: task kworker/1:7:9832 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:kworker/1:7 state:D stack:22288 pid:9832 tgid:9832 ppid:2 flags:0x00004000 Workqueue: events console_callback 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_timeout+0x258/0x2a0 kernel/time/timer.c:2591 ___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:2808 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:3120 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 Showing all locks held in the system: 7 locks held by kworker/0:0/8: 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 6 locks held by kworker/0:2/1124: #0: ffff888106aac148 ((wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900020dfd80 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810b342190 (&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: ffff88810b345508 (&port_dev->status_lock){+.+.}-{3:3} , at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] , at: hub_port_connect drivers/usb/core/hub.c:5418 [inline] , at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] , at: port_event drivers/usb/core/hub.c:5821 [inline] , at: hub_event+0x28aa/0x4f40 drivers/usb/core/hub.c:5903 #4: ffff88810779a268 (hcd->address0_mutex){+.+.}-{3:3} , at: hub_port_connect drivers/usb/core/hub.c:5419 [inline] , at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] , at: port_event drivers/usb/core/hub.c:5821 [inline] , at: hub_event+0x28d0/0x4f40 drivers/usb/core/hub.c:5903 #5: ffffffff899cb5f0 (ehci_cf_port_reset_rwsem ){.+.+}-{3:3}, at: hub_port_reset+0x1a7/0x1e60 drivers/usb/core/hub.c:3021 2 locks held by getty/2925: #0: ffff8881154410a0 ( &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 4 locks held by kworker/1:4/5255: 4 locks held by kworker/0:4/5373: 4 locks held by udevd/5918: #0: ffff8881063d19e0 (&p->lock){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff8881182aa488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810febea58 (kn->active){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88810afaa190 (&dev->mutex ){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] ){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 4 locks held by udevd/7364: #0: ffff88812b19d790 (&p->lock){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888114171888 (&of->mutex ){+.+.}-{3:3} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810779be18 ( kn->active){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88810b342190 ( &dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] &dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 4 locks held by kworker/0:3/9426: 2 locks held by kworker/1:7/9832: #0: ffff888100080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90001e0fd80 (console_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 5 locks held by kworker/0:8/11302: #0: ffff888106aac148 ((wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000144fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810afba190 ( &dev->mutex ){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] ){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88810afbd508 (&port_dev->status_lock ){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] ){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5418 [inline] ){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] ){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] ){+.+.}-{3:3}, at: hub_event+0x28aa/0x4f40 drivers/usb/core/hub.c:5903 #4: ffff88810fec7a68 ( hcd->address0_mutex ){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5419 [inline] ){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] ){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] ){+.+.}-{3:3}, at: hub_event+0x28d0/0x4f40 drivers/usb/core/hub.c:5903 3 locks held by kworker/1:0/19207: ============================================= 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: 20191 Comm: kworker/0:9 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 legacy_dvb_usb_read_remote_control RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:413 Code: 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 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d c3 cc cc cc cc e8 11 e5 0d ff eb a0 e8 9a e5 0d RSP: 0018:ffffc90012b0f6f8 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff82a096d5 RDI: ffffffff936336a0 RBP: ffffffff93633660 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff936336b0 R15: 000000000000002f FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001840 CR3: 00000001177ba000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_clear_IER+0x9b/0xc0 drivers/tty/serial/8250/8250_port.c:699 serial8250_console_write+0x243/0x17c0 drivers/tty/serial/8250/8250_port.c:3358 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x800/0xc60 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0xd9/0x210 kernel/printk/printk.c:3279 vprintk_emit+0x424/0x6f0 kernel/printk/printk.c:2407 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 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: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