INFO: task syz-executor.0:13247 can't die for more than 143 seconds. syz-executor.0 D28968 13247 8686 0x00004006 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 schedule+0xa8/0x270 kernel/sched/core.c:3944 perf_event_free_task+0x50d/0x6d0 kernel/events/core.c:11606 copy_process+0x45d4/0x6b00 kernel/fork.c:2283 _do_fork+0x146/0xfa0 kernel/fork.c:2369 __do_sys_clone kernel/fork.c:2524 [inline] __se_sys_clone kernel/fork.c:2505 [inline] __x64_sys_clone+0x18d/0x250 kernel/fork.c:2505 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: dd fe ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 48 83 ec 28 48 89 6c 24 20 48 <8d> 6c 24 20 48 8b 44 24 30 48 89 04 24 48 8b 4c 24 38 48 89 4c 24 RSP: 002b:00007f5228ecec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459829 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000002102001ffe RBP: 000000000075bf20 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5228ecf6d4 R13: 00000000004bfce6 R14: 00000000004d17f8 R15: 00000000ffffffff INFO: task syz-executor.0:13247 blocked for more than 143 seconds. Not tainted 5.3.0-rc1-next-20190724 #50 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28968 13247 8686 0x00004006 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x755/0x1580 kernel/sched/core.c:3880 schedule+0xa8/0x270 kernel/sched/core.c:3944 perf_event_free_task+0x50d/0x6d0 kernel/events/core.c:11606 copy_process+0x45d4/0x6b00 kernel/fork.c:2283 _do_fork+0x146/0xfa0 kernel/fork.c:2369 __do_sys_clone kernel/fork.c:2524 [inline] __se_sys_clone kernel/fork.c:2505 [inline] __x64_sys_clone+0x18d/0x250 kernel/fork.c:2505 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: dd fe ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 76 68 48 83 ec 28 48 89 6c 24 20 48 <8d> 6c 24 20 48 8b 44 24 30 48 89 04 24 48 8b 4c 24 38 48 89 4c 24 RSP: 002b:00007f5228ecec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459829 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000002102001ffe RBP: 000000000075bf20 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5228ecf6d4 R13: 00000000004bfce6 R14: 00000000004d17f8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1053: #0: 00000000e6a86c16 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5257 1 lock held by rsyslogd/8555: #0: 00000000044c6db8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8645: #0: 00000000fcda5e60 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d530c077 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8646: #0: 000000009af8af26 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a93f9fc7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8647: #0: 0000000006042b6f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000021e475b5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8648: #0: 00000000e4fae33c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000348a3306 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8649: #0: 0000000046bb1a2d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008685a5d4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8650: #0: 000000005eb0d524 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000af61bedc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/8651: #0: 0000000027ac4c91 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a75b3dc3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1053 Comm: khungtaskd Not tainted 5.3.0-rc1-next-20190724 #50 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+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:249 [inline] watchdog+0xc54/0x1320 kernel/hung_task.c:333 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60