INFO: task kworker/1:4:5723 blocked for more than 143 seconds. Not tainted 6.12.0-rc6-syzkaller-00128-g12bbabd3cab8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:20944 pid:5723 tgid:5723 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: 1 lock held by khungtaskd/30: #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 2 locks held by getty/2920: #0: ffff88811241f0a0 (&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 2 locks held by kworker/1:4/5723: #0: ffff888100080948 ((wq_completion)events){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000cee7d80 (console_work){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 4 locks held by udevd/5731: #0: ffff888118d19418 (&p->lock ){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff8881380cd488 (&of->mutex #2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88810feb40f8 (kn->active#5){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88810af32190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 4 locks held by udevd/5735: #0: ffff8881173e82f0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888118a42c88 (&of->mutex#2 ){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811e744698 (kn->active#5){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888106f40190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff888106f40190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 5 locks held by kworker/0:5/5804: #0: ffff8881062cb548 ((wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000fa1fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810abeb190 (&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: ffff888106f40190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888117e62160 ( &dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 5 locks held by kworker/1:6/5924: #0: ffff8881062cb548 ((wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000fb0fd80 ( (work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810ab37190 ( &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: ffff88811407a190 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff8881166a2160 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 4 locks held by udevd/6029: #0: ffff88811c0a38b8 (&p->lock){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888137598c88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888121a0e4b8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888132063190 ( &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 6 locks held by kworker/1:0/8585: #0: ffff8881062cb548 ( (wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900027efd80 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810af32190 ( &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: ffff888131a25190 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88811407c160 (&dev->mutex ){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] ){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffff8881381f1bd8 (&dev->ctrl_urb_lock){+.+.}-{3:3}, at: em28xx_write_regs_req+0x14c/0x410 drivers/media/usb/em28xx/em28xx-core.c:147 3 locks held by kworker/1:7/9771: 3 locks held by kworker/1:8/10262: 3 locks held by kworker/1:10/11239: 4 locks held by kworker/0:12/11411: 1 lock held by syz.4.2450/12694: 1 lock held by syz.0.2451/12700: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00128-g12bbabd3cab8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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: 10965 Comm: kworker/1:9 Not tainted 6.12.0-rc6-syzkaller-00128-g12bbabd3cab8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 7e 60 e8 a3 ff ff ff 31 c0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 48 8b 15 e4 d0 ad 7e 65 8b 05 e5 d0 ad 7e a9 00 01 RSP: 0018:ffffc9000235f400 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 00000000fffffffe RCX: ffffffff86e848ca RDX: ffff888116a71d40 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffffc9000235f5e0 R08: 0000000000000005 R09: 0000000000000000 R10: 00000000fffffffe R11: 0000000000644658 R12: ffffffff8728c7c2 R13: 00000000fffffffe R14: ffffc9000235f4f0 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8881f5900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f38f3222000 CR3: 000000012df30000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x1b6/0x1880 lib/vsprintf.c:2790 snprintf+0xc8/0x100 lib/vsprintf.c:2938 print_caller kernel/printk/printk.c:1371 [inline] info_print_prefix+0x135/0x350 kernel/printk/printk.c:1390 record_print_text+0x141/0x400 kernel/printk/printk.c:1437 printk_get_next_message+0x2a6/0x670 kernel/printk/printk.c:2978 console_emit_next_record kernel/printk/printk.c:3046 [inline] console_flush_all+0x6ec/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_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: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