INFO: task kworker/0:4:5275 blocked for more than 143 seconds. Not tainted 6.12.0-rc4-syzkaller-00052-gc6d9e43954bf #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:21424 pid:5275 tgid:5275 ppid:2 flags:0x00004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x105f/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: 3 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: ffff88810ab58190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f40 drivers/usb/core/hub.c:5849 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 6 locks held by kworker/1:1/41: 2 locks held by getty/2920: #0: ffff88811215f0a0 (&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 7 locks held by kworker/0:3/5264: 2 locks held by kworker/0:4/5275: #0: ffff888100080948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900020ffd80 (console_work){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 5 locks held by kworker/0:9/10870: #0: ffff888105ef6d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900119ffd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810ab22190 ( &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: ffff88811422d190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] ffff88811422d190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888116212160 ( &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 5 locks held by kworker/1:12/11615: 4 locks held by kworker/0:10/13146: 1 lock held by syz.3.2932/14374: 1 lock held by sed/14379: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc4-syzkaller-00052-gc6d9e43954bf #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13590 Comm: kworker/0:14 Not tainted 6.12.0-rc4-syzkaller-00052-gc6d9e43954bf #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:246 Code: cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 af d0 ad 7e <65> 8b 05 b0 d0 ad 7e a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 RSP: 0018:ffffc90000007bb0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffffffff84b12551 RDX: ffff888112a257c0 RSI: 0000000000000002 RDI: 0000000000000005 RBP: ffffffff87b2d420 R08: 0000000000000005 R09: 0000000000000002 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000005 R14: 0000000000000004 R15: 1ffff92000000fad FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2cf1fffc CR3: 000000011713e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:351 dummy_timer+0xf1/0x3930 drivers/usb/gadget/udc/dummy_hcd.c:1798 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1755 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1772 handle_softirqs+0x206/0x8d0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xac/0x110 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 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 9c 93 1f 00 9c 41 5c 41 81 e4 00 02 00 00 31 ff 4c 89 e6 e8 f8 95 1f 00 4d 85 e4 0f 85 8d 00 00 00 7a 93 1f 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc9001294fb10 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 000000000000003e RCX: ffffffff81365fbe RDX: ffff888112a257c0 RSI: ffffffff81365fc8 RDI: 0000000000000007 RBP: 1ffff92002529f64 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000200 R14: ffff88810228d7c0 R15: ffffc9001294fbf8 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:68 _printk+0xc8/0x100 kernel/printk/printk.c:2432 dvb_usb_read_remote_control+0x174/0x1c0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:263 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