INFO: task syz-executor.5:25116 blocked for more than 140 seconds. Not tainted 4.14.143 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28528 25116 6820 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_timeout+0x93b/0xe10 kernel/time/timer.c:1721 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common kernel/sched/completion.c:123 [inline] wait_for_completion+0x27c/0x420 kernel/sched/completion.c:144 kthread_stop+0xda/0x650 kernel/kthread.c:530 sdr_cap_stop_streaming+0x1fc/0x320 drivers/media/platform/vivid/vivid-sdr-cap.c:313 __vb2_queue_cancel+0xa3/0x890 drivers/media/v4l2-core/videobuf2-core.c:1655 vb2_core_streamoff+0x52/0x110 drivers/media/v4l2-core/videobuf2-core.c:1788 __vb2_cleanup_fileio+0x78/0x150 drivers/media/v4l2-core/videobuf2-core.c:2313 vb2_core_queue_release+0x1d/0x80 drivers/media/v4l2-core/videobuf2-core.c:2040 vb2_queue_release drivers/media/v4l2-core/videobuf2-v4l2.c:669 [inline] _vb2_fop_release+0x1cf/0x2a0 drivers/media/v4l2-core/videobuf2-v4l2.c:840 vb2_fop_release+0x75/0xc0 drivers/media/v4l2-core/videobuf2-v4l2.c:854 vivid_fop_release+0x180/0x3f0 drivers/media/platform/vivid/vivid-core.c:486 v4l2_release+0xf9/0x190 drivers/media/v4l2-core/v4l2-dev.c:446 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4bc/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4135d1 RSP: 002b:00007ffd407ed130 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00000000004135d1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000001 R08: ffffffff8100791e R09: 00000000e1ded0b8 R10: 00007ffd407ed210 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000762748 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1013: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/6651: #0: (&p->pi_lock){-.-.}, at: [] __fget+0x47/0x370 fs/file.c:684 2 locks held by getty/6773: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6774: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6775: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6776: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6777: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6778: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6779: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1013 Comm: khungtaskd Not tainted 4.14.143 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x197 lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.143 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_tt_purge task: ffff8880a9cc2140 task.stack: ffff8880a9cd0000 RIP: 0010:arch_local_irq_disable arch/x86/include/asm/paravirt.h:784 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:797 [inline] RIP: 0010:lock_release+0xd8/0x940 kernel/locking/lockdep.c:4006 RSP: 0018:ffff8880a9cd7b80 EFLAGS: 00000286 RAX: 0000000000000286 RBX: 1ffff1101539af76 RCX: 000000002c0c1592 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880a9cc29bc RBP: ffff8880a9cd7c18 R08: 0000000000005c63 R09: ffffffff88cad798 R10: 0000000000000000 R11: ffff8880a9cc2140 R12: ffff888062f45da0 R13: ffffffff86074f32 R14: ffff8880a9cc2140 R15: ffff8880a9cd7bf0 FS: 0000000000000000(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd7d4049140 CR3: 000000008ad9b000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:174 [inline] _raw_spin_unlock_bh+0x1b/0x40 kernel/locking/spinlock.c:208 spin_unlock_bh include/linux/spinlock.h:362 [inline] batadv_tt_local_purge+0x242/0x320 net/batman-adv/translation-table.c:1435 batadv_tt_purge+0x2e/0x9b0 net/batman-adv/translation-table.c:3742 process_one_work+0x863/0x1600 kernel/workqueue.c:2114 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 10 00 0f 85 cb 06 00 00 48 83 3d c3 1e 29 06 00 0f 84 3f 05 00 00 9c 58 0f 1f 44 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 45 88 <48> c7 c0 10 54 71 87 48 c1 e8 03 80 3c 10 00 0f 85 58 06 00 00