INFO: task syz-executor.0:21964 blocked for more than 140 seconds. Not tainted 4.19.86-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28216 21964 7457 0x80000002 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782 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 vivid_stop_generating_vid_cap+0x1e0/0x6e2 drivers/media/platform/vivid/vivid-kthread-cap.c:922 vid_cap_stop_streaming+0x8a/0xe0 drivers/media/platform/vivid/vivid-vid-cap.c:256 __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 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x994/0x2fa0 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+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: Bad RIP value. RSP: 002b:00007ffe3f643c98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 000000000045a639 RDX: 0000000000414111 RSI: 0000000000a770d0 RDI: 0000000000000000 RBP: 00000000004bff37 R08: 000000000000000c R09: 00007ffe3f643da0 R10: 0000000000f41940 R11: 0000000000000246 R12: 000000000075bfc8 R13: 0000000000000004 R14: 0000000000000001 R15: 000000000075bfd4 Showing all locks held in the system: 1 lock held by khungtaskd/1039: #0: 00000000353574c7 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by udevd/3592: 1 lock held by rsyslogd/7291: #0: 0000000023e82941 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7413: #0: 0000000039675024 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000006a593392 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7414: #0: 00000000a7f3a37a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b3176bea (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7415: #0: 0000000016917c79 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000b5de3a9a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7416: #0: 00000000f4b579b6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000004e6675fc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7417: #0: 000000002fc039b1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000009d4cae9d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7418: #0: 000000005a0944c1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000004313fc0f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7419: #0: 0000000090685026 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000108a8bb3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1039 Comm: khungtaskd Not tainted 4.19.86-syzkaller #0 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+0x197/0x210 lib/dump_stack.c:118 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3592 Comm: udevd Not tainted 4.19.86-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:28 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/kasan.c:211 [inline] RIP: 0010:memory_is_poisoned mm/kasan/kasan.c:241 [inline] RIP: 0010:check_memory_region_inline mm/kasan/kasan.c:257 [inline] RIP: 0010:check_memory_region+0x3a/0x190 mm/kasan/kasan.c:267 Code: 7f ff ff 55 0f b6 d2 48 39 c7 48 89 e5 41 55 41 54 53 0f 86 f6 00 00 00 4c 8d 5c 37 ff 49 89 f8 48 b8 00 00 00 00 00 fc ff df <4d> 89 da 49 c1 e8 03 4d 8d 24 00 49 c1 ea 03 49 01 c2 4c 89 e0 49 RSP: 0018:ffff8880978efa28 EFLAGS: 00000212 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff86f1a3a7 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888097b18cc0 RBP: ffff8880978efa40 R08: ffff888097b18cc0 R09: ffffed1012f63199 R10: ffffed1012f63198 R11: ffff888097b18cc7 R12: fffffbfff146f8dc R13: ffff888097b18cc0 R14: ffff8880978e4680 R15: 0000000000000000 FS: 00007fd2b13827a0(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000097863000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278 atomic64_cmpxchg include/asm-generic/atomic-instrumented.h:63 [inline] __mutex_trylock_or_owner kernel/locking/mutex.c:110 [inline] __mutex_trylock kernel/locking/mutex.c:125 [inline] __mutex_lock_common kernel/locking/mutex.c:927 [inline] __mutex_lock+0x397/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 ep_scan_ready_list+0x8cd/0xb20 fs/eventpoll.c:690 ep_send_events fs/eventpoll.c:1713 [inline] ep_poll+0x3b4/0xd10 fs/eventpoll.c:1840 do_epoll_wait+0x1b3/0x200 fs/eventpoll.c:2198 __do_sys_epoll_wait fs/eventpoll.c:2208 [inline] __se_sys_epoll_wait fs/eventpoll.c:2205 [inline] __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2205 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fd2b0a96943 Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24 RSP: 002b:00007ffd1f6262c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007fd2b0a96943 RDX: 0000000000000008 RSI: 00007ffd1f6263c0 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000b4a2e0 R15: 0000000000b00030