INFO: task kworker/1:4:19519 blocked for more than 143 seconds. Not tainted 6.6.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:23120 pid:19519 ppid:2 flags:0x00004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0xc79/0x30a0 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_timeout+0x278/0x2c0 kernel/time/timer.c:2143 ___down_common kernel/locking/semaphore.c:225 [inline] __down_common+0x327/0x6c0 kernel/locking/semaphore.c:246 down+0x74/0xa0 kernel/locking/semaphore.c:63 console_lock+0x96/0x150 kernel/printk/printk.c:2652 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:2933 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff87eac820 (rcu_read_lock){....}-{1:2} , at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] , at: rcu_read_lock include/linux/rcupdate.h:749 [inline] , at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 2 locks held by getty/2446: #0: ffff8881130500a0 (&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+0xfc5/0x1480 drivers/tty/n_tty.c:2206 4 locks held by kworker/0:11/17616: #0: ffff88810ae51138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000d2a7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 #2: ffff888106797190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #2: ffff888106797190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f30 drivers/usb/core/hub.c:5768 #3: ffff88811c481190 ( &dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] &dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 2 locks held by kworker/1:4/19519: #0: ffff888100070d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000562fd80 (console_work){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 7 locks held by kworker/1:11/22988: 3 locks held by kworker/1:13/26000: 3 locks held by kworker/0:4/27275: 4 locks held by udevd/27999: #0: ffff8881332e71c8 (&p->lock ){+.+.}-{3:3} , at: seq_read_iter+0xda/0x1280 fs/seq_file.c:182 #1: ffff888137226088 (&of->mutex ){+.+.}-{3:3}, at: kernfs_seq_start+0x4b/0x460 fs/kernfs/file.c:154 #2: ffff888112822a00 (kn->active#25){++++}-{0:0}, at: kernfs_seq_start+0x6f/0x460 fs/kernfs/file.c:155 #3: ffff88811c481190 (&dev->mutex){....}-{3:3}, at: device_lock_interruptible include/linux/device.h:997 [inline] (&dev->mutex){....}-{3:3}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 3 locks held by kworker/1:10/28670: 5 locks held by kworker/1:14/28671: 3 locks held by kworker/1:2/30953: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x26c/0x2d0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 28438 Comm: kworker/0:15 Not tainted 6.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:unwind_next_frame+0x731/0x2390 arch/x86/kernel/unwind_orc.c:517 Code: ba 00 00 00 00 00 fc ff df 48 c1 e8 03 0f b6 0c 10 49 8d 44 24 01 48 89 c6 48 c1 ee 03 0f b6 14 16 4c 89 e6 83 e6 07 40 38 f1 <40> 0f 9e c6 84 c9 0f 95 c1 40 84 ce 0f 85 9c 19 00 00 83 e0 07 38 RSP: 0018:ffffc90000007628 EFLAGS: 00000097 RAX: ffffffff8982a6c5 RBX: ffffc900000076a8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000009 R10: 0000000000000005 R11: 0000000000003dc1 R12: ffffffff8982a6c4 R13: 0000000000000005 R14: ffffffff8982a6c8 R15: ffffc90009fe7f30 FS: 0000000000000000(0000) GS:ffff8881f6600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555564f5818 CR3: 000000011d2b8000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x13c/0x190 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xff/0x330 mm/slub.c:3822 dummy_timer+0x13ac/0x35f0 drivers/usb/gadget/udc/dummy_hcd.c:1981 call_timer_fn+0x19e/0x580 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x764/0xb10 kernel/time/timer.c:2022 run_timer_softirq+0x58/0xd0 kernel/time/timer.c:2035 __do_softirq+0x20b/0x94e kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xa7/0x110 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x8e/0xb0 arch/x86/kernel/apic/apic.c:1074 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1979 [inline] RIP: 0010:vprintk_emit+0x3aa/0x5f0 kernel/printk/printk.c:2306 Code: 00 4d 85 e4 0f 85 e4 01 00 00 e8 11 20 1c 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 8f 1b 1c 00 48 85 ed 0f 85 f0 01 00 00 f1 1f 1c 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc90009fe7b10 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 000000000000003a RCX: 0000000000000000 RDX: ffff888106fa5700 RSI: ffffffff81315524 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0a2e746e65766520 R12: 0000000000000200 R13: ffff888104e5d700 R14: ffffffff87105f20 R15: ffffc90009fe7b90 vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2332 legacy_dvb_usb_read_remote_control+0x403/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:124 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304