INFO: task syz-executor2:14689 blocked for more than 140 seconds. Not tainted 4.18.0+ #195 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D23736 14689 4422 0x00000004 Call Trace: context_switch kernel/sched/core.c:2823 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3471 schedule+0xfb/0x450 kernel/sched/core.c:3515 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+0xa41/0x1616 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 mount_fs+0xae/0x328 fs/super.c:1280 vfs_kern_mount.part.34+0xdc/0x4e0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2542 [inline] do_mount+0x581/0x30e0 fs/namespace.c:2872 ksys_mount+0x12d/0x140 fs/namespace.c:3088 __do_sys_mount fs/namespace.c:3102 [inline] __se_sys_mount fs/namespace.c:3099 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3099 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: Bad RIP value. RSP: 002b:00007f9c1ebddc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f9c1ebde6d4 RCX: 0000000000457089 RDX: 0000000020000180 RSI: 00000000200000c0 RDI: 0000000000000000 RBP: 0000000000930320 R08: 00000000200001c0 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/774: #0: 000000009d6c4d87 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 2 locks held by rs:main Q:Reg/4281: #0: 00000000c7e27f14 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 000000006166bb04 (sb_writers#6){.+.+}, at: file_start_write include/linux/fs.h:2755 [inline] #1: 000000006166bb04 (sb_writers#6){.+.+}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4283: 2 locks held by getty/4373: #0: 000000009f6efeb7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fb3ce939 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4374: #0: 0000000048e9f519 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e75b27a3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4375: #0: 000000005bafcee9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001716d88f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4376: #0: 00000000cf129485 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fc80d2d5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4377: #0: 000000003f017022 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000040cea658 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4378: #0: 000000007e7cc568 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000b977823a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4379: #0: 000000006fa76b6d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000b07d7230 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by kworker/0:4/5161: #0: 00000000604f7e23 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000604f7e23 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000604f7e23 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000604f7e23 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000604f7e23 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000604f7e23 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000604f7e23 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124 #1: 000000000028837a ((work_completion)(&m->wq)){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 774 Comm: khungtaskd Not tainted 4.18.0+ #195 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:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.18.0+ #195 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:try_to_wake_up+0x222/0x12a0 kernel/sched/core.c:2026 Code: 00 00 00 00 fc ff df 4c 89 d2 48 c1 ea 03 c6 04 02 04 48 89 ca 48 c1 ea 03 0f b6 14 02 48 89 c8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 a2 0c 00 00 4c 89 d6 41 8b 45 38 48 ba 00 00 00 00 00 RSP: 0018:ffff8801db107590 EFLAGS: 00000006 RAX: 0000000000000003 RBX: ffff8801db107750 RCX: ffff8801d9ee22b8 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000082 RBP: ffff8801db107778 R08: ffffed003b6246d7 R09: 0000000000000001 R10: ffff8801db107690 R11: ffff8801db1236b3 R12: ffff8801d9ee2290 R13: ffff8801d9ee2280 R14: ffff8801d9ee22bc R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000010cd000 CR3: 00000001b0948000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: wake_up_process+0x10/0x20 kernel/sched/core.c:2123 process_timeout+0x31/0x40 kernel/time/timer.c:1733 call_timer_fn+0x242/0x970 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7dc/0xcb0 kernel/time/timer.c:1682 run_timer_softirq+0x1d/0x40 kernel/time/timer.c:1695 __do_softirq+0x2eb/0xb1e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x1d6/0x210 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x18e/0x730 arch/x86/kernel/apic/apic.c:1056 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:56 Code: c7 48 89 45 d8 e8 aa 35 05 fb 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 99 35 05 fb eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffff8801d9f27c38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 1ffff1003b3e4f8a RCX: 0000000000000000 RDX: 1ffffffff0fe3750 RSI: 0000000000000001 RDI: ffffffff87f1ba80 RBP: ffff8801d9f27c38 R08: ffffed003b6246d7 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801d9f27cf0 R14: ffffffff888b00a0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xc7/0x450 arch/x86/kernel/process.c:498 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3aa/0x570 kernel/sched/idle.c:262 cpu_startup_entry+0x10c/0x120 kernel/sched/idle.c:368 start_secondary+0x433/0x5d0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242