INFO: task syz-executor868:5860 blocked for more than 140 seconds. Not tainted 4.19.0+ #91 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor868 D21848 5860 5859 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_timeout+0x1cc/0x260 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+0x427/0x8a0 kernel/sched/completion.c:136 kthread_stop+0x1a9/0x900 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x2bc/0x93b drivers/media/platform/vivid/vivid-kthread-cap.c:919 vid_cap_stop_streaming+0x8d/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:259 __vb2_queue_cancel+0x171/0xca0 drivers/media/common/videobuf2/videobuf2-core.c:1668 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1804 __vb2_cleanup_fileio+0x73/0x160 drivers/media/common/videobuf2/videobuf2-core.c:2325 vb2_core_queue_release+0x1e/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2052 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 [inline] _vb2_fop_release+0x1d2/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:843 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:857 vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x400ef0 Code: 00 00 47 02 00 00 ed 00 00 00 00 00 00 00 73 02 00 00 00 00 00 00 a8 01 00 00 00 00 00 00 36 01 00 00 b5 00 00 00 01 02 00 00 <00> 00 00 00 00 00 00 00 6a 01 00 00 00 00 00 00 00 00 00 00 00 00 RSP: 002b:00007fffb4af6128 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400ef0 RDX: 000000000000004a RSI: 0000000020000040 RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000208f880 R09: 00000000004002e0 R10: 000000000000000f R11: 0000000000000246 R12: 0000000000401e00 R13: 0000000000401e90 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor868:5957 blocked for more than 140 seconds. Not tainted 4.19.0+ #91 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor868 D21848 5957 5855 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_timeout+0x1cc/0x260 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+0x427/0x8a0 kernel/sched/completion.c:136 kthread_stop+0x1a9/0x900 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x2bc/0x93b drivers/media/platform/vivid/vivid-kthread-cap.c:919 vid_cap_stop_streaming+0x8d/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:259 __vb2_queue_cancel+0x171/0xca0 drivers/media/common/videobuf2/videobuf2-core.c:1668 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1804 __vb2_cleanup_fileio+0x73/0x160 drivers/media/common/videobuf2/videobuf2-core.c:2325 vb2_core_queue_release+0x1e/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2052 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 [inline] _vb2_fop_release+0x1d2/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:843 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:857 vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x400ef0 Code: 00 00 47 02 00 00 ed 00 00 00 00 00 00 00 73 02 00 00 00 00 00 00 a8 01 00 00 00 00 00 00 36 01 00 00 b5 00 00 00 01 02 00 00 <00> 00 00 00 00 00 00 00 6a 01 00 00 00 00 00 00 00 00 00 00 00 00 RSP: 002b:00007fffb4af6128 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400ef0 RDX: 000000000000004a RSI: 0000000020000040 RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000208f880 R09: 00000000004002e0 R10: 000000000000000f R11: 0000000000000246 R12: 0000000000027359 R13: 0000000000401e90 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor868:6074 blocked for more than 140 seconds. Not tainted 4.19.0+ #91 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor868 D24208 6074 5856 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_timeout+0x1cc/0x260 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+0x427/0x8a0 kernel/sched/completion.c:136 kthread_stop+0x1a9/0x900 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x2bc/0x93b drivers/media/platform/vivid/vivid-kthread-cap.c:919 vid_cap_stop_streaming+0x8d/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:259 __vb2_queue_cancel+0x171/0xca0 drivers/media/common/videobuf2/videobuf2-core.c:1668 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1804 __vb2_cleanup_fileio+0x73/0x160 drivers/media/common/videobuf2/videobuf2-core.c:2325 vb2_core_queue_release+0x1e/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2052 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 [inline] _vb2_fop_release+0x1d2/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:843 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:857 vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x400ef0 Code: 00 00 47 02 00 00 ed 00 00 00 00 00 00 00 73 02 00 00 00 00 00 00 a8 01 00 00 00 00 00 00 36 01 00 00 b5 00 00 00 01 02 00 00 <00> 00 00 00 00 00 00 00 6a 01 00 00 00 00 00 00 00 00 00 00 00 00 RSP: 002b:00007fffb4af6128 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400ef0 RDX: 000000000000004a RSI: 0000000020000040 RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000208f880 R09: 00000000004002e0 R10: 000000000000000f R11: 0000000000000246 R12: 000000000002742e R13: 0000000000401e90 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor868:6177 blocked for more than 140 seconds. Not tainted 4.19.0+ #91 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor868 D24208 6177 5854 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_timeout+0x1cc/0x260 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+0x427/0x8a0 kernel/sched/completion.c:136 kthread_stop+0x1a9/0x900 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x2bc/0x93b drivers/media/platform/vivid/vivid-kthread-cap.c:919 vid_cap_stop_streaming+0x8d/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:259 __vb2_queue_cancel+0x171/0xca0 drivers/media/common/videobuf2/videobuf2-core.c:1668 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1804 __vb2_cleanup_fileio+0x73/0x160 drivers/media/common/videobuf2/videobuf2-core.c:2325 vb2_core_queue_release+0x1e/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2052 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 [inline] _vb2_fop_release+0x1d2/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:843 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:857 vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x400ef0 Code: 00 00 47 02 00 00 ed 00 00 00 00 00 00 00 73 02 00 00 00 00 00 00 a8 01 00 00 00 00 00 00 36 01 00 00 b5 00 00 00 01 02 00 00 <00> 00 00 00 00 00 00 00 6a 01 00 00 00 00 00 00 00 00 00 00 00 00 RSP: 002b:00007fffb4af6128 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400ef0 RDX: 000000000000004a RSI: 0000000020000040 RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000208f880 R09: 00000000004002e0 R10: 000000000000000f R11: 0000000000000246 R12: 0000000000027501 R13: 0000000000401e90 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor868:6180 blocked for more than 140 seconds. Not tainted 4.19.0+ #91 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor868 D24208 6180 5857 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_timeout+0x1cc/0x260 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+0x427/0x8a0 kernel/sched/completion.c:136 kthread_stop+0x1a9/0x900 kernel/kthread.c:550 vivid_stop_generating_vid_cap+0x2bc/0x93b drivers/media/platform/vivid/vivid-kthread-cap.c:919 vid_cap_stop_streaming+0x8d/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:259 __vb2_queue_cancel+0x171/0xca0 drivers/media/common/videobuf2/videobuf2-core.c:1668 vb2_core_streamoff+0x60/0x140 drivers/media/common/videobuf2/videobuf2-core.c:1804 __vb2_cleanup_fileio+0x73/0x160 drivers/media/common/videobuf2/videobuf2-core.c:2325 vb2_core_queue_release+0x1e/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2052 vb2_queue_release drivers/media/common/videobuf2/videobuf2-v4l2.c:672 [inline] _vb2_fop_release+0x1d2/0x2b0 drivers/media/common/videobuf2/videobuf2-v4l2.c:843 vb2_fop_release+0x77/0xc0 drivers/media/common/videobuf2/videobuf2-v4l2.c:857 vivid_fop_release+0x18e/0x440 drivers/media/platform/vivid/vivid-core.c:474 v4l2_release+0xfb/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 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+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x400ef0 Code: 00 00 47 02 00 00 ed 00 00 00 00 00 00 00 73 02 00 00 00 00 00 00 a8 01 00 00 00 00 00 00 36 01 00 00 b5 00 00 00 01 02 00 00 <00> 00 00 00 00 00 00 00 6a 01 00 00 00 00 00 00 00 00 00 00 00 00 RSP: 002b:00007fffb4af6128 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000400ef0 RDX: 000000000000004a RSI: 0000000020000040 RDI: 0000000000000003 RBP: 0000000000000000 R08: 000000000208f880 R09: 00000000004002e0 R10: 000000000000000f R11: 0000000000000246 R12: 0000000000027507 R13: 0000000000401e90 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1007: #0: 0000000079fe5785 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 2 locks held by rsyslogd/5700: #0: 00000000a8202ff0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 000000008dbb8b6b (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1126 [inline] #1: 000000008dbb8b6b (&rq->lock){-.-.}, at: __schedule+0x236/0x21d0 kernel/sched/core.c:3410 2 locks held by getty/5823: #0: 00000000eaddb0f5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002bba59fb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5824: #0: 00000000be235ef1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c9512bce (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5825: #0: 00000000876d77fe (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000010504277 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5826: #0: 00000000452bfd9e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001f32a3ce (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5827: #0: 00000000c77f887f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e2a02f99 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5828: #0: 0000000059d53103 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002bb0ee9d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5829: #0: 00000000920abd97 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005fee3904 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1007 Comm: khungtaskd Not tainted 4.19.0+ #91 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+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.1+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57