INFO: task syz-executor.3:9957 blocked for more than 140 seconds. Not tainted 4.19.34 #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28216 9957 8036 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x817/0x1d00 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 schedule_timeout+0x8ca/0xfd0 kernel/time/timer.c:1780 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136 kthread_stop+0x116/0x6d0 kernel/kthread.c:550 sdr_cap_stop_streaming+0x213/0x330 drivers/media/platform/vivid/vivid-sdr-cap.c:301 __vb2_queue_cancel+0xb4/0x970 drivers/media/common/videobuf2/videobuf2-core.c:1662 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1796 __vb2_cleanup_fileio+0x78/0x170 drivers/media/common/videobuf2/videobuf2-core.c:2323 vb2_core_queue_release+0x20/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2050 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:671 [inline] _vb2_fop_release+0x1cf/0x2a0 drivers/media/common/videobuf2/videobuf2-v4l2.c:842 vb2_fop_release+0x75/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:856 vivid_fop_release+0x18e/0x430 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x2df/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4120b1 Code: 00 74 1b 48 83 ec 08 e8 ed 8e ff ff 48 c7 05 d2 b5 24 00 00 00 00 00 31 c0 48 83 c4 08 c3 31 c0 c3 0f 1f 84 00 00 00 00 00 48 <83> ec 08 b9 40 96 65 00 31 d2 be 53 25 44 00 bf 52 37 44 00 ff 15 RSP: 002b:00007fffdb3bd170 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00000000004120b1 RDX: 0000000000000000 RSI: 00000000007402c0 RDI: 0000000000000005 RBP: 000000000073c900 R08: ffffffff812f902a R09: 00000000ffc15122 R10: 00007fffdb3bd240 R11: 0000000000000293 R12: ffffffffffffffff R13: 000000000001d1b1 R14: 00000000000003e8 R15: 000000000073bf0c Showing all locks held in the system: 2 locks held by kworker/u4:3/981: #0: 00000000be3e5631 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9563 [inline] #0: 00000000be3e5631 (&rq->lock){-.-.}, at: pick_next_task_fair+0xaf6/0x1550 kernel/sched/fair.c:6749 #1: 000000008165dbce (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:5966 1 lock held by khungtaskd/1033: #0: 000000008165dbce (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7861: #0: 00000000bb22c494 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7983: #0: 000000002f5476cc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000e209d710 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7984: #0: 00000000bf81698d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000000faf75f2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7985: #0: 000000007d15a83a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000fa53597c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7986: #0: 000000003fb0ae30 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000005d60c398 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7987: #0: 00000000fc4a86d9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000004656e2ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7988: #0: 000000008a4610bb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000043a6484e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7989: #0: 000000002ae30bf7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000001559e6d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1033 Comm: khungtaskd Not tainted 4.19.34 #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:202 [inline] watchdog+0x9c6/0xec0 kernel/hung_task.c:263 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 981 Comm: kworker/u4:3 Not tainted 4.19.34 #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:2837 [inline] RIP: 0010:lockdep_hardirqs_on+0x1f5/0x5d0 kernel/locking/lockdep.c:2879 Code: 8b 83 68 08 00 00 85 c0 0f 85 2f 02 00 00 48 8d bb 30 08 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 87 03 00 00 48 8d bb 28 08 00 00 4c 89 a3 30 08 00 00 48 b8 RSP: 0018:ffff8880a8127bc0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8880a8118680 RCX: 1ffff110150231e9 RDX: 1ffff110150231d6 RSI: ffff8880a8118f28 RDI: ffff8880a8118eb0 RBP: ffff8880a8127bd0 R08: ffff8880a8118680 R09: ffff8880a8118f48 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8140a0da R13: ffffffff86eedbb1 R14: ffffffff8140a0da R15: 0000000000000023 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000a0d43000 CR4: 00000000001406e0 Call Trace: trace_hardirqs_on+0x67/0x230 kernel/trace/trace_preemptirq.c:30 __local_bh_enable_ip+0x15a/0x270 kernel/softirq.c:194 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x31/0x40 kernel/locking/spinlock.c:200 spin_unlock_bh include/linux/spinlock.h:374 [inline] batadv_nc_purge_paths+0x267/0x370 net/batman-adv/network-coding.c:482 batadv_nc_worker+0x2cf/0x760 net/batman-adv/network-coding.c:733 process_one_work+0x98e/0x1760 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413