INFO: task syz-executor2:10572 blocked for more than 140 seconds. Not tainted 4.19.0+ #313 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D18568 10572 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __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 fs/pipe.c:83 [inline] pipe_write+0xc0/0xec0 fs/pipe.c:366 call_write_iter include/linux/fs.h:1839 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x410f40 Code: 40 48 89 6c 24 38 48 8d 6c 24 38 48 8b 44 24 48 48 8d 88 00 20 00 00 48 39 c1 0f 82 e0 00 00 00 48 89 c1 48 c1 e8 0d 48 f7 c1 1f 00 00 74 03 48 ff c0 48 89 44 24 28 48 89 c1 48 c1 e0 0d 48 RSP: 002b:0000000000a3d568 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000000000c RCX: 0000000000410f40 RDX: 000000000000000c RSI: 0000000000a3d700 RDI: 0000000000000002 RBP: 0000000000a3d700 R08: 0000000002581940 R09: 000000000000000c R10: 0000000002581940 R11: 0000000000000246 R12: 000000000000000c R13: 0000000000000001 R14: 000000000070cf20 R15: 0000000000000002 Showing all locks held in the system: 2 locks held by kworker/0:1/12: #0: 0000000041e20a2f ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:206 [inline] #0: 0000000041e20a2f ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000041e20a2f ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 0000000041e20a2f ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 0000000041e20a2f ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 0000000041e20a2f ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 0000000041e20a2f ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000cb63ea3d ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 1 lock held by khungtaskd/1009: #0: 0000000060dc8ac1 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5571: #0: 0000000025386501 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5661: #0: 0000000025c1f58c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000007f5ced82 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5662: #0: 000000002c684023 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000080c4fed2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5663: #0: 00000000ff5f57b5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000002751a5c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5664: #0: 00000000aebc8bd6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000b33cfb5d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5665: #0: 000000009e9df870 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000c11b989 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5666: #0: 00000000734dce56 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c006d854 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/5667: #0: 000000004307d2cf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000087f66ab2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 1 lock held by syz-executor2/10572: #0: 00000000d605069b (&pipe->mutex/1){+.+.}, at: __pipe_lock fs/pipe.c:83 [inline] #0: 00000000d605069b (&pipe->mutex/1){+.+.}, at: pipe_write+0xc0/0xec0 fs/pipe.c:366 1 lock held by syz-executor2/11586: #0: 00000000d605069b (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000d605069b (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 1 lock held by syz-executor2/11630: #0: 00000000162ae935 (&pipe->mutex/1){+.+.}, at: pipe_lock_nested fs/pipe.c:62 [inline] #0: 00000000162ae935 (&pipe->mutex/1){+.+.}, at: pipe_lock+0x6e/0x80 fs/pipe.c:70 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1009 Comm: khungtaskd Not tainted 4.19.0+ #313 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.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57