INFO: task syz-executor537:7906 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-executor537 D28216 7906 7888 0x80000002 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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x933/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:979 __do_sys_exit_group kernel/exit.c:990 [inline] __se_sys_exit_group kernel/exit.c:988 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:988 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x443b98 Code: Bad RIP value. RSP: 002b:00007fff968471d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000443b98 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004c3510 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 000000000000000f R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d5180 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1032: #0: 0000000078b663b3 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7737: #0: 0000000061f858c8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7859: #0: 00000000ebfb04b4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000005b2401a1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7860: #0: 00000000cb4e3ab2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000e4f5051b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7861: #0: 000000008011de0e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000001a304561 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7862: #0: 0000000030f8edee (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000b88c0400 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7863: #0: 00000000b9b6f64f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000b23a7e5d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7864: #0: 0000000064396e2f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000075f9bef5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7865: #0: 00000000617cb016 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000002e8db158 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 1 lock held by vivid-005-sdr-c/21755: #0: 00000000112f7f4b (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9563 [inline] #0: 00000000112f7f4b (&rq->lock){-.-.}, at: pick_next_task_fair+0xaf6/0x1550 kernel/sched/fair.c:6749 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1032 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 21759 Comm: vivid-001-sdr-c Not tainted 4.19.34 #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_lockdep_rcu_enabled+0x2e/0xa0 kernel/rcu/update.c:253 Code: 34 3b 89 55 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 89 e5 48 c1 e9 03 83 c0 03 0f b6 14 11 38 d0 7c 04 84 d2 75 49 <8b> 15 5c ca e2 07 85 d2 74 3b 48 c7 c0 c0 9b b0 88 48 ba 00 00 00 RSP: 0000:ffff888099577c60 EFLAGS: 00000246 RAX: 0000000000000003 RBX: ffff888085c12040 RCX: 1ffffffff127668a RDX: 0000000000000000 RSI: ffffffff81668a71 RDI: ffff888085c13108 RBP: ffff888099577c60 R08: ffff888085c12040 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff887bec60 R14: ffff888085c12040 R15: ffffffff887c7e20 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000042d9e0 CR3: 0000000082115000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: task_css include/linux/cgroup.h:478 [inline] pids_release+0x3f/0x250 kernel/cgroup/pids.c:252 cgroup_release+0x102/0x190 kernel/cgroup/cgroup.c:5685 release_task+0xc80/0x1630 kernel/exit.c:222 exit_notify kernel/exit.c:746 [inline] do_exit+0x14fc/0x2fa0 kernel/exit.c:896 kthread+0x2c3/0x430 kernel/kthread.c:248 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413