INFO: task syz-executor1:9498 blocked for more than 140 seconds. Not tainted 4.19.0+ #313 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D23384 9498 5763 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: 0033:0x411021 Code: 83 c4 40 c3 48 8d 05 d8 f9 48 00 48 89 04 24 48 c7 44 24 08 0d 00 00 00 e8 ac a8 01 00 0f 0b 48 8d 05 bd f9 48 00 48 89 04 24 <48> c7 44 24 08 0d 00 00 00 e8 91 a8 01 00 0f 0b e8 1a 8f 04 00 e9 RSP: 002b:0000000000a3fd90 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000411021 RDX: 0000001b33b20000 RSI: 0000000000730318 RDI: 0000000000000003 RBP: 0000000000000000 R08: ffffffff8139bae3 R09: 00000000e2abfaac R10: 0000000000a3fcc0 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 000000000000005b R15: 0000000000000001 INFO: task syz-executor5:9516 blocked for more than 140 seconds. Not tainted 4.19.0+ #313 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D23384 9516 5904 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: 0033:0x411021 Code: 83 c4 40 c3 48 8d 05 d8 f9 48 00 48 89 04 24 48 c7 44 24 08 0d 00 00 00 e8 ac a8 01 00 0f 0b 48 8d 05 bd f9 48 00 48 89 04 24 <48> c7 44 24 08 0d 00 00 00 e8 91 a8 01 00 0f 0b e8 1a 8f 04 00 e9 RSP: 002b:0000000000a3fd90 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000411021 RDX: 0000001b33b20000 RSI: 0000000000730318 RDI: 0000000000000003 RBP: 0000000000000000 R08: ffffffff8139bae3 R09: 00000000e2abfaac R10: 0000000000a3fcc0 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000066 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: 00000000a217052e (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5540: #0: 00000000f23326c8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5630: #0: 00000000f4a374d2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000682c89cb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5631: #0: 00000000ba0fb4e0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000045df6aa7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5632: #0: 000000003e3b7ed5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000af8ac745 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5633: #0: 00000000d6005602 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000461463c1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5634: #0: 0000000070bc5c8b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000df08820f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5635: #0: 000000007d564ffa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ccb140b4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5636: #0: 00000000567887b9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007f7e7cad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1008 Comm: khungtaskd Not tainted 4.19.0+ #313 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.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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 0 to CPUs 1: INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.212 msecs NMI backtrace for cpu 1 CPU: 1 PID: 5656 Comm: syz-fuzzer Not tainted 4.19.0+ #313 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:update_nohz_stats+0x55/0x220 kernel/sched/fair.c:7840 Code: fb 49 8d 14 04 48 83 ec 68 48 c7 45 80 b0 fc 0f 89 48 c7 85 78 ff ff ff b3 8a b5 41 48 c7 45 88 f0 1b 59 81 c7 02 f1 f1 f1 f1 42 04 00 f2 f2 f2 4c 89 ea 65 48 8b 0c 25 28 00 00 00 48 89 4d RSP: 0018:ffff8801c821e1c0 EFLAGS: 00000086 RAX: dffffc0000000000 RBX: ffff8801daf2ccc0 RCX: 0000000000000001 RDX: ffffed0039043c39 RSI: 0000000000000000 RDI: ffff8801daf2ccc0 RBP: ffff8801c821e250 R08: 0000000000000001 R09: ffffffff89246028 R10: ffffed0039043cea R11: ffff8801c821e757 R12: 1ffff10039043c39 R13: ffff8801daf2cd40 R14: 000000000002ccc0 R15: dffffc0000000000 FS: 000000c420026068(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2f31d4a000 CR3: 00000001d700b000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: update_sg_lb_stats kernel/sched/fair.c:7883 [inline] update_sd_lb_stats+0x9c8/0x3230 kernel/sched/fair.c:8084 find_busiest_group+0xf9/0x2060 kernel/sched/fair.c:8362 load_balance+0x687/0x39a0 kernel/sched/fair.c:8659 idle_balance kernel/sched/fair.c:9622 [inline] pick_next_task_fair+0x63b/0x1b30 kernel/sched/fair.c:6723 pick_next_task kernel/sched/core.c:3318 [inline] __schedule+0x487/0x21d0 kernel/sched/core.c:3446 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_hrtimeout_range_clock+0x23f/0x490 kernel/time/hrtimer.c:1947 schedule_hrtimeout_range+0x2a/0x40 kernel/time/hrtimer.c:1992 poll_schedule_timeout.constprop.11+0x127/0x210 fs/select.c:243 do_select+0x15d1/0x1ac0 fs/select.c:576 core_sys_select+0x77f/0xc50 fs/select.c:650 do_pselect+0x43c/0x4e0 fs/select.c:731 __do_sys_pselect6 fs/select.c:772 [inline] __se_sys_pselect6 fs/select.c:757 [inline] __x64_sys_pselect6+0x1f7/0x280 fs/select.c:757 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45d911 Code: 0f 00 f7 f1 48 89 04 24 b8 e8 03 00 00 f7 e2 48 89 44 24 08 31 ff 31 f6 31 d2 45 31 d2 49 89 e0 45 31 c9 b8 0e 01 00 00 0f 05 <48> 8b 6c 24 10 48 83 c4 18 c3 cc cc cc cc cc b8 ba 00 00 00 0f 05 RSP: 002b:000000c420035f18 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045d911 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000c420035f28 R08: 000000c420035f18 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000430120 R13: 00000000000000f1 R14: 0000000000000011 R15: 0000000000000000