INFO: task kworker/0:7:11880 blocked for more than 144 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/0:7 state:D stack:22384 pid:11880 tgid:11880 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] ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] ffffffff88ebb140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 2 locks held by getty/2917: #0: ffff888100eac0a0 (&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 6 locks held by kworker/1:5/5253: #0: ffff8881062cb548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9000213fd80 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff88810af81190 (&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 #3: ffff8881354de190 ( &dev->mutex ){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff888108bac160 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:1014 [inline] , at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffff88811513dbd8 (&dev->ctrl_urb_lock){+.+.}-{3:3}, at: em28xx_write_regs_req+0x14c/0x410 drivers/media/usb/em28xx/em28xx-core.c:147 4 locks held by udevd/8681: #0: ffff888112c1fb08 (&p->lock){+.+.}-{3:3} , at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff8881315afc88 (&of->mutex #2){+.+.}-{3:3} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888111668a58 ( kn->active#5){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff8881354de190 ( &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 udevd/8683: #0: ffff88811902ae80 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff888119194c88 (&of->mutex#2){+.+.}-{3:3} , at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff888135343a58 (kn->active#5 ){++++}-{0:0} , at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888107e85190 (&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 3 locks held by kworker/1:7/9901: 2 locks held by kworker/0:7/11880: #0: ffff888100080948 ((wq_completion)events ){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90012347d80 (console_work ){+.+.}-{0:0} , at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 5 locks held by kworker/1:8/13367: 3 locks held by kworker/0:11/14599: 1 lock held by syz.8.2754/16243: #0: ffffffff88ec6a38 (rcu_state.exp_mutex){+.+.}-{3:3} , at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 ============================================= 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: 14599 Comm: kworker/0:11 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:number+0x9a/0xb80 lib/vsprintf.c:472 Code: 04 25 28 00 00 00 48 89 84 24 e8 00 00 00 31 c0 48 89 4c 24 70 e8 26 e0 6e fa 48 8d 7c 24 70 48 89 f8 48 c1 e8 03 0f b6 0c 28 <48> 8d 44 24 77 48 89 c2 48 c1 ea 03 0f b6 14 2a 80 f9 00 40 0f 9e RSP: 0018:ffffc90003c17240 EFLAGS: 00000a06 RAX: 1ffff92000782e56 RBX: ffffc90003c1761f RCX: 0000000000000000 RDX: ffff888113cad7c0 RSI: ffffffff86e712ea RDI: ffffc90003c172b0 RBP: dffffc0000000000 R08: 0000000000000005 R09: 000000000000002f R10: 0000000000000018 R11: 00000000007e6870 R12: ffffffff8728c78b R13: ffffc90003c174c8 R14: ffffc90083c17617 R15: 0000000000000009 FS: 0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa347453ff0 CR3: 000000011676c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vsnprintf+0x92a/0x1880 lib/vsprintf.c:2869 sprintf+0xcd/0x110 lib/vsprintf.c:3007 print_time kernel/printk/printk.c:1362 [inline] info_print_prefix+0x25c/0x350 kernel/printk/printk.c:1388 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_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