INFO: task syz-executor5:10088 blocked for more than 140 seconds. Not tainted 4.19.0+ #83 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D25208 10088 5701 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480 schedule+0xfe/0x460 kernel/sched/core.c:3524 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3582 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 pipe_lock_nested fs/pipe.c:62 [inline] pipe_lock+0x6e/0x80 fs/pipe.c:70 do_splice+0xe79/0x1430 fs/splice.c:1171 __do_sys_splice fs/splice.c:1415 [inline] __se_sys_splice fs/splice.c:1395 [inline] __x64_sys_splice+0x2c1/0x330 fs/splice.c:1395 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f5fd3f57c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 000000000072bf00 R08: 000000000000ced1 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5fd3f586d4 R13: 00000000004c4f4f R14: 00000000004d7a40 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/981: #0: 000000002bd0cceb (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5425: #0: 000000004acf8c09 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5515: #0: 0000000021818563 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000528a2cb1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5516: #0: 00000000345d74c5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c954a24d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5517: #0: 000000006377a8f2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dd10324b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5518: #0: 0000000017c9262b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000069a6af30 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5519: #0: 000000008ea16ef5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005c1272b5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5520: #0: 00000000f0833ae0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000082c37a5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5521: #0: 000000006c6be6cd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000052cca9ff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 1 lock held by syz-executor5/10029: #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 1 lock held by syz-executor5/10088: #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 1 lock held by syz-executor5/11832: #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 1 lock held by syz-executor5/13092: #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 0000000033d65110 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 1 lock held by syz-executor5/14398: #0: 00000000e8d76a4b (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000e8d76a4b (&pipe->mutex/1){+.+.}, at: pipe_release+0x4e/0x270 fs/pipe.c:564 1 lock held by syz-executor5/14401: #0: 00000000e8d76a4b (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000e8d76a4b (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 1 lock held by syz-executor5/14409: #0: 00000000c8e71b5d (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000c8e71b5d (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 981 Comm: khungtaskd Not tainted 4.19.0+ #83 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.1+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57