NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.1:8066 blocked for more than 140 seconds. Not tainted 4.14.174-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28464 8066 7387 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x946/0xe40 kernel/time/timer.c:1723 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common kernel/sched/completion.c:123 [inline] wait_for_completion+0x241/0x390 kernel/sched/completion.c:144 flush_work+0x3f5/0x780 kernel/workqueue.c:2893 __cancel_work_timer+0x2d0/0x460 kernel/workqueue.c:2964 p9_conn_destroy net/9p/trans_fd.c:872 [inline] p9_fd_close+0x28d/0x420 net/9p/trans_fd.c:899 p9_client_create+0x787/0x10f0 net/9p/client.c:1095 v9fs_session_init+0x1dc/0x1620 fs/9p/v9fs.c:422 v9fs_mount+0x79/0x850 fs/9p/vfs_super.c:135 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x3c0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x3c9/0x24f0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c849 RSP: 002b:00007f2b2f121c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f2b2f1226d4 RCX: 000000000045c849 RDX: 0000000020000200 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 000000000076bfa0 R08: 0000000020000040 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000074a R14: 00000000004ca085 R15: 000000000076bfac Showing all locks held in the system: 2 locks held by kworker/1:1/23: #0: ("events"){+.+.}, at: [] work_static include/linux/workqueue.h:199 [inline] #0: ("events"){+.+.}, at: [] set_work_data kernel/workqueue.c:619 [inline] #0: ("events"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ("events"){+.+.}, at: [] process_one_work+0x727/0x1540 kernel/workqueue.c:2087 #1: ((&m->rq)){+.+.}, at: [] process_one_work+0x761/0x1540 kernel/workqueue.c:2091 1 lock held by khungtaskd/1057: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/7338: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7339: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7340: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7341: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7342: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/7343: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 2 locks held by getty/8016: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16f0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1057 Comm: khungtaskd Not tainted 4.14.174-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff864064de