INFO: task syz-executor.2:4801 blocked for more than 140 seconds. Not tainted 4.19.64 #38 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28216 4801 25414 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 schedule_timeout+0x8c8/0xfc0 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+0x116/0x6c0 kernel/kthread.c:550 sdr_cap_stop_streaming+0x213/0x330 drivers/media/platform/vivid/vivid-sdr-cap.c:301 __vb2_queue_cancel+0xb1/0x790 drivers/media/common/videobuf2/videobuf2-core.c:1682 vb2_core_streamoff+0x60/0x150 drivers/media/common/videobuf2/videobuf2-core.c:1816 __vb2_cleanup_fileio+0x78/0x170 drivers/media/common/videobuf2/videobuf2-core.c:2343 vb2_core_queue_release+0x20/0x80 drivers/media/common/videobuf2/videobuf2-core.c:2070 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+0xf9/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:448 __fput+0x2dd/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x145/0x1c0 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:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413511 Code: c8 48 c1 e8 03 48 83 c0 03 48 c1 e8 02 48 8b 8c 24 90 00 00 00 48 c1 e9 05 48 8b 54 24 68 48 89 d3 48 29 c2 48 29 cb 48 89 d8 <48> ff c0 48 89 04 24 48 29 da 48 89 54 24 08 e8 6b 6c 04 00 48 8b RSP: 002b:00007ffe8f0b6c50 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413511 RDX: 0000001b2ff20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: ffffffff8130e19c R09: 00000000fb6a436f R10: 00007ffe8f0b6d30 R11: 0000000000000293 R12: 000000000075bfc8 R13: 000000000017ad07 R14: 0000000000760228 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1039: #0: 0000000066c870af (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435 3 locks held by rs:main Q:Reg/7701: 1 lock held by rsyslogd/7704: 2 locks held by getty/7830: #0: 0000000027448bec (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000003be2ef9f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7831: #0: 00000000867ca742 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000008676c92f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7832: #0: 000000003d13e42f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000043d32d3d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7833: #0: 0000000030055d20 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000044aa4c48 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7834: #0: 00000000c9669c27 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000006a6095d8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7835: #0: 000000009b0a7033 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000002ba32be6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7836: #0: 00000000a1394f41 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000938ee570 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1039 Comm: khungtaskd Not tainted 4.19.64 #38 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:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.64 #38 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lock_is_held_type+0x0/0x210 kernel/locking/lockdep.c:3931 Code: c3 48 8b 7d c8 e8 d0 1c 50 00 e9 27 ff ff ff 48 8b 7d c8 e8 c2 1c 50 00 e9 60 ff ff ff e8 b8 1c 50 00 eb ac 66 0f 1f 44 00 00 <48> b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 55 41 54 49 89 fc 53 RSP: 0018:ffff8880aa27fc60 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffff8880aa278000 RCX: 1ffffffff1161f30 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8879f0a0 RBP: ffff8880aa27fd38 R08: ffff8880aa2703c0 R09: ffffed1015d25bdd R10: ffffed1015d25bdc R11: ffff8880ae92dee7 R12: 0000000000000000 R13: 000000000002d240 R14: ffff8880aa2703c0 R15: ffff8880ae92d240 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c423b7e000 CR3: 00000000a7c89000 CR4: 00000000001406e0 Call Trace: schedule_idle+0x58/0x80 kernel/sched/core.c:3545 do_idle+0x192/0x560 kernel/sched/idle.c:286 cpu_startup_entry+0xc8/0xe0 kernel/sched/idle.c:368 start_secondary+0x3e8/0x5b0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243