INFO: task syz-executor.4:14851 blocked for more than 143 seconds. Not tainted 5.1.0-rc4+ #66 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29320 14851 7844 0x20020004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 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 __io_uring_register+0xb6/0x1fd0 fs/io_uring.c:2925 __do_sys_io_uring_register fs/io_uring.c:2975 [inline] __se_sys_io_uring_register fs/io_uring.c:2957 [inline] __ia32_sys_io_uring_register+0x193/0x1f0 fs/io_uring.c:2957 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x281/0xc98 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f3f869 Code: Bad RIP value. RSP: 002b:00000000f5d3b0cc EFLAGS: 00000296 ORIG_RAX: 00000000000001ab RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000020001700 RSI: 0000000000000002 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor.4:14905 blocked for more than 143 seconds. Not tainted 5.1.0-rc4+ #66 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D30016 14905 7844 0x20020004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 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:2674 [inline] __se_sys_io_uring_enter fs/io_uring.c:2633 [inline] __ia32_sys_io_uring_enter+0x67f/0xac0 fs/io_uring.c:2633 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x281/0xc98 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f3f869 Code: Bad RIP value. RSP: 002b:00000000f5d1a0cc EFLAGS: 00000296 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000000 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 0000000020000080 RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by kworker/u4:1/21: #0: 0000000053939758 (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:10053 [inline] #0: 0000000053939758 (&rq->lock){-.-.}, at: pick_next_task_fair+0x1214/0x19a0 kernel/sched/fair.c:7062 #1: 00000000197e748c (rcu_read_lock){....}, at: __update_idle_core+0x45/0x3f0 kernel/sched/fair.c:6059 1 lock held by khungtaskd/1042: #0: 00000000197e748c (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5056 1 lock held by rsyslogd/7702: #0: 00000000042d380f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7792: #0: 000000004a185007 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000be4c7398 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7793: #0: 00000000cd4e3a94 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000f780c4b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7794: #0: 00000000e33c38c3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000170fc1b8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7795: #0: 00000000cc2765c2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000006b4b9a46 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7796: #0: 0000000011fff5a1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000d7cdf14 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7797: #0: 00000000e2c55132 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f437234a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7798: #0: 00000000693e195c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009a6d81ac (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.4/14851: #0: 00000000c3bdf206 (&ctx->uring_lock){+.+.}, at: __do_sys_io_uring_register fs/io_uring.c:2974 [inline] #0: 00000000c3bdf206 (&ctx->uring_lock){+.+.}, at: __se_sys_io_uring_register fs/io_uring.c:2957 [inline] #0: 00000000c3bdf206 (&ctx->uring_lock){+.+.}, at: __ia32_sys_io_uring_register+0x182/0x1f0 fs/io_uring.c:2957 1 lock held by syz-executor.4/14905: #0: 00000000c3bdf206 (&ctx->uring_lock){+.+.}, at: __do_sys_io_uring_enter fs/io_uring.c:2674 [inline] #0: 00000000c3bdf206 (&ctx->uring_lock){+.+.}, at: __se_sys_io_uring_enter fs/io_uring.c:2633 [inline] #0: 00000000c3bdf206 (&ctx->uring_lock){+.+.}, at: __ia32_sys_io_uring_enter+0x67f/0xac0 fs/io_uring.c:2633 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc4+ #66 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 1 to CPUs 0: