INFO: task syz-executor.1:13823 blocked for more than 143 seconds. Not tainted 5.1.0-rc4+ #59 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28384 13823 7817 0x80000000 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 schedule_timeout+0x8ca/0xfd0 kernel/time/timer.c:1779 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 exit_aio+0x321/0x3a0 fs/aio.c:897 __mmput kernel/fork.c:1043 [inline] mmput+0xcf/0x4c0 kernel/fork.c:1067 exit_mm kernel/exit.c:546 [inline] do_exit+0x816/0x2fa0 kernel/exit.c:863 do_group_exit+0x135/0x370 kernel/exit.c:980 get_signal+0x399/0x1d50 kernel/signal.c:2577 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4582f9 Code: 24 20 48 8b 42 08 48 89 44 24 18 48 63 4a 10 48 89 4c 24 10 e8 78 3f fd ff 48 8d 05 9a 70 48 00 48 89 04 24 48 c7 44 24 08 11 <00> 00 00 e8 ff 48 fd ff 48 8b 44 24 18 48 89 04 24 e8 b1 48 fd ff RSP: 002b:00007fff3f5fed48 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffdfc RBX: 000000000000002d RCX: 00000000004582f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000073bf0c RBP: 000000000073bf00 R08: 0000000000042af5 R09: 0000000000042af5 R10: 00007fff3f5fee10 R11: 0000000000000246 R12: 0000000000042b6c R13: 0000000000042b3f R14: 00000000000003e8 R15: 000000000073bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1041: #0: 000000001c186643 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061 2 locks held by rsyslogd/7690: #0: 000000008e469d0b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 00000000c290fd70 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #1: 00000000c290fd70 (&rq->lock){-.-.}, at: __schedule+0x1fc/0x1cc0 kernel/sched/core.c:3456 2 locks held by getty/7779: #0: 00000000affbc4bd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004f2989e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7780: #0: 00000000d5a11271 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f5e0c9d3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7781: #0: 000000009c3a67f7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d43021c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7782: #0: 00000000313100fe (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007db07868 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7783: #0: 00000000a7011591 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000050d58423 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7784: #0: 00000000c73048e8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005ded4a91 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7785: #0: 000000006d15caef (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000065e1d0cf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.1.0-rc4+ #59 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+0x1be/0x236 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:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: