INFO: task kworker/0:4:5263 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/0:4 state:D stack:21472 pid:5263 tgid:5263 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: 6 locks held by kworker/0:1/9: #0: ffff888105ef6d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000009fd80 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810b3a9190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff88810b3a9190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 #3: ffff88811cb4f190 (&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 #4: ffff88814285f160 ( &dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff89c7a1a8 (dvbdev_register_lock){+.+.}-{3:3}, at: dvb_register_device+0x48/0x2000 drivers/media/dvb-core/dvbdev.c:460 1 lock held by khungtaskd/30: #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 2 locks held by getty/2921: #0: ffff888107f7d0a0 (&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 udevd/5228: #0: ffff888132b809e0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888131293c88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88811ac0c1e8 (kn->active#4){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88811cb4f190 (&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/5249: #0: ffff888119a9b2f0 (&p->lock){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888105ad2c88 (&of->mutex#2){+.+.}-{3:3} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888107bf2878 (kn->active#4 ){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff88810abfe190 ( &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 2 locks held by kworker/0:4/5263: #0: ffff888100080948 ((wq_completion)events ){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90001fefd80 (console_work){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 5 locks held by kworker/0:0/8421: #0: ffff888105ef6d48 ((wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000187fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810abfe190 (&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: ffff88811d2e5190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff88811cb4b160 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 3 locks held by kworker/0:7/8614: 3 locks held by kworker/1:8/9354: 3 locks held by kworker/1:12/13913: 1 lock held by syz.2.2998/15215: 1 lock held by syz.4.3001/15222: ============================================= 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: 10276 Comm: kworker/0:8 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:match_held_lock+0x65/0xc0 kernel/locking/lockdep.c:5302 Code: d1 aa 8f 48 c1 f8 03 48 0f af c2 0f b7 53 20 5b 81 e2 ff 1f 00 00 48 39 d0 0f 94 c0 0f b6 c0 c3 cc cc cc cc b8 01 00 00 00 5b cc cc cc cc 31 f6 e8 2f fe ff ff 48 85 c0 75 a7 31 c0 5b c3 cc RSP: 0018:ffffc90000007c98 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff88813931e2a8 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff8881f583c618 RDI: ffff88813931e2a8 RBP: ffff8881f583c618 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88813931d7c0 R13: ffff88813931e258 R14: 00000000ffffffff R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb56df94fe0 CR3: 000000010d3e0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held kernel/locking/lockdep.c:5566 [inline] lock_is_held_type+0xb0/0x150 kernel/locking/lockdep.c:5897 lock_is_held include/linux/lockdep.h:249 [inline] worker_set_flags kernel/workqueue.c:976 [inline] wq_worker_tick+0x3c2/0x470 kernel/workqueue.c:1498 sched_tick+0x238/0x2d0 kernel/sched/core.c:5622 update_process_times+0x19c/0x220 kernel/time/timer.c:2524 tick_sched_handle kernel/time/tick-sched.c:276 [inline] tick_nohz_handler+0x376/0x530 kernel/time/tick-sched.c:297 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x5fb/0xae0 kernel/time/hrtimer.c:1755 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1817 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x8b/0xb0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2042 [inline] RIP: 0010:vprintk_emit+0x621/0x6f0 kernel/printk/printk.c:2406 Code: 85 ed 0f 85 81 00 00 00 e8 0c 94 1f 00 9c 41 5c 41 81 e4 00 02 00 00 31 ff 4c 89 e6 e8 68 96 1f 00 4d 85 e4 0f 85 8d 00 00 00 ea 93 1f 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc9001634fa80 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 000000000000003a RCX: ffffffff81365f9e RDX: ffff88813931d7c0 RSI: ffffffff81365fa8 RDI: 0000000000000007 RBP: 1ffff92002c69f52 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000200 R14: ffff88810228d7c0 R15: ffffc9001634fb68 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 legacy_dvb_usb_read_remote_control+0x40d/0x500 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124 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