kworker/dying (22) used greatest stack depth: 15352 bytes left INFO: task syz-executor6:24655 blocked for more than 140 seconds. Not tainted 4.18.0-next-20180815+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D21480 24655 4478 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x87c/0x1df0 kernel/sched/core.c:3473 schedule+0xfb/0x450 kernel/sched/core.c:3517 schedule_timeout+0x1cc/0x260 kernel/time/timer.c:1780 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+0x430/0x8d0 kernel/sched/completion.c:136 flush_work+0x531/0x900 kernel/workqueue.c:2918 __cancel_work_timer+0x4bd/0x830 kernel/workqueue.c:2989 cancel_work_sync+0x17/0x20 kernel/workqueue.c:3025 p9_conn_destroy net/9p/trans_fd.c:865 [inline] p9_fd_close+0x376/0x5c0 net/9p/trans_fd.c:891 p9_client_create+0x9bc/0x150c net/9p/client.c:1065 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135 legacy_get_tree+0x131/0x460 fs/fs_context.c:732 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1746 do_new_mount fs/namespace.c:2627 [inline] do_mount+0x6f9/0x1e30 fs/namespace.c:2951 ksys_mount+0x12d/0x140 fs/namespace.c:3167 __do_sys_mount fs/namespace.c:3181 [inline] __se_sys_mount fs/namespace.c:3178 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3178 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007f76c08b2c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f76c08b36d4 RCX: 0000000000457089 RDX: 0000000020000340 RSI: 00000000200000c0 RDI: 0000000000000000 RBP: 0000000000930320 R08: 00000000200003c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d2768 R14: 00000000004c7be5 R15: 0000000000000004 Showing all locks held in the system: 1 lock held by khungtaskd/775: #0: 000000002278ba40 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4436 2 locks held by kworker/0:2/1883: #0: 000000009370aba8 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 000000009370aba8 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 000000009370aba8 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 000000009370aba8 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 000000009370aba8 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 000000009370aba8 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 000000009370aba8 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1aa0 kernel/workqueue.c:2124 #1: 000000000484288f ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0xb9b/0x1aa0 kernel/workqueue.c:2128 2 locks held by rsyslogd/4335: #0: 000000000a424313 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 00000000693b2eba (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1821 [inline] #1: 00000000693b2eba (&rq->lock){-.-.}, at: __schedule+0x24d/0x1df0 kernel/sched/core.c:3411 2 locks held by getty/4426: #0: 000000007fb2f7aa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005f82dede (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4427: #0: 00000000a678918a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000af2eeb8e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4428: #0: 00000000ecd206c3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000050e0f0df (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4429: #0: 00000000e23b507c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000db94d346 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4430: #0: 00000000ed35e654 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000001bde10d9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4431: #0: 00000000704b98dd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000bfe0ec83 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4432: #0: 000000003f78472f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000004ec01e3d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 775 Comm: khungtaskd Not tainted 4.18.0-next-20180815+ #40 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x48/0x88 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x151/0x192 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+0xb39/0x1040 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 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:56