INFO: task syz-executor.2:8915 blocked for more than 143 seconds. Not tainted 5.1.0-rc4-next-20190412 #24 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29480 8915 7840 0x00000004 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+0x717/0xc50 kernel/time/timer.c:1783 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 __io_uring_register+0xb6/0x1fd0 fs/io_uring.c:2926 __do_sys_io_uring_register fs/io_uring.c:2976 [inline] __se_sys_io_uring_register fs/io_uring.c:2958 [inline] __x64_sys_io_uring_register+0x193/0x1f0 fs/io_uring.c:2958 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c29 Code: cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 df 00 00 00 48 83 ec 30 48 89 6c 24 28 48 8d 6c 24 28 48 8b 42 08 48 8b 48 70 <48> 89 4c 24 20 48 8b 10 48 89 54 24 18 48 8b 40 08 48 89 44 24 10 RSP: 002b:00007f45dff55c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458c29 RDX: 0000000020000240 RSI: 0000000000000002 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000005b R11: 0000000000000246 R12: 00007f45dff566d4 R13: 00000000004cb698 R14: 00000000004d2138 R15: 00000000ffffffff INFO: task syz-executor.2:8923 blocked for more than 143 seconds. Not tainted 5.1.0-rc4-next-20190412 #24 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D30336 8923 7840 0x00000004 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_preempt_disabled+0x13/0x20 kernel/sched/core.c:3620 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 __do_sys_io_uring_enter fs/io_uring.c:2675 [inline] __se_sys_io_uring_enter fs/io_uring.c:2634 [inline] __x64_sys_io_uring_enter+0x67f/0xac0 fs/io_uring.c:2634 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c29 Code: Bad RIP value. RSP: 002b:00007f45dff34c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000458c29 RDX: 0000000000000009 RSI: 0000000000000096 RDI: 0000000000000003 RBP: 000000000073bfa0 R08: 0000000020000080 R09: 0000000000000008 R10: 0000000000000001 R11: 0000000000000246 R12: 00007f45dff356d4 R13: 00000000004bfe3c R14: 00000000004d2120 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 000000002d501ac2 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061 1 lock held by rsyslogd/7707: #0: 000000003f140e22 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7798: #0: 0000000044a76914 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000fbac2d1e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7799: #0: 000000002913755f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d132ff4e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7800: #0: 00000000b62285cb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b2cde163 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7801: #0: 00000000e83442c8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000008760b68 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7802: #0: 00000000950de6b5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000260cac17 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7803: #0: 000000004648c80f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d422fec9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7804: #0: 00000000ae46d1f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004ac915e2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:5/7901: #0: 000000002b27d65b (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:10053 [inline] #0: 000000002b27d65b (&rq->lock){-.-.}, at: pick_next_task_fair+0x1214/0x19a0 kernel/sched/fair.c:7062 #1: 000000002d501ac2 (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6059 #2: 000000000b298801 (&base->lock){-.-.}, at: lock_timer_base+0x56/0x1b0 kernel/time/timer.c:932 1 lock held by syz-executor.2/8915: #0: 0000000001dde8dc (&ctx->uring_lock){+.+.}, at: __do_sys_io_uring_register fs/io_uring.c:2975 [inline] #0: 0000000001dde8dc (&ctx->uring_lock){+.+.}, at: __se_sys_io_uring_register fs/io_uring.c:2958 [inline] #0: 0000000001dde8dc (&ctx->uring_lock){+.+.}, at: __x64_sys_io_uring_register+0x182/0x1f0 fs/io_uring.c:2958 1 lock held by syz-executor.2/8923: #0: 0000000001dde8dc (&ctx->uring_lock){+.+.}, at: __do_sys_io_uring_enter fs/io_uring.c:2675 [inline] #0: 0000000001dde8dc (&ctx->uring_lock){+.+.}, at: __se_sys_io_uring_enter fs/io_uring.c:2634 [inline] #0: 0000000001dde8dc (&ctx->uring_lock){+.+.}, at: __x64_sys_io_uring_enter+0x67f/0xac0 fs/io_uring.c:2634 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc4-next-20190412 #24 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:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: