INFO: task syz-executor.0:6001 blocked for more than 143 seconds. Not tainted 5.0.0-next-20190306 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28376 6001 7765 0x80000002 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3620 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 vhost_net_stop_vq+0x2d/0x120 drivers/vhost/net.c:1360 vhost_net_stop drivers/vhost/net.c:1374 [inline] vhost_net_release+0x5d/0x260 drivers/vhost/net.c:1406 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x90a/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:980 __do_sys_exit_group kernel/exit.c:991 [inline] __se_sys_exit_group kernel/exit.c:989 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:989 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458079 Code: Bad RIP value. RSP: 002b:00007ffd14f3f2d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000458079 RDX: 0000000000411d71 RSI: 0000000000a54ef0 RDI: 0000000000000000 RBP: 00000000004bd682 R08: 000000000000000c R09: 00007ffd14f3f3e0 R10: 00000000028da940 R11: 0000000000000246 R12: 000000000073bfac R13: 0000000000000001 R14: 0000000000000003 R15: 000000000073bfac Showing all locks held in the system: 1 lock held by khungtaskd/1044: #0: 00000000efe54ab3 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5052 1 lock held by rsyslogd/7636: #0: 00000000a6e39b5c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7727: #0: 00000000e48cdd81 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a5a9b34f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7728: #0: 000000005b639071 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003bd1ade6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7729: #0: 000000004b69559e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008a397c98 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7730: #0: 000000006eaf43b3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d3ac07fc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7731: #0: 000000008ecacead (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000664fd8eb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7732: #0: 0000000045c646b7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000320c18aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7733: #0: 00000000182d215a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000fc615112 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/6001: #0: 00000000d11275df (&vq->mutex){+.+.}, at: vhost_net_stop_vq+0x2d/0x120 drivers/vhost/net.c:1360 1 lock held by vhost-6002/6003: 1 lock held by syz-executor.3/25997: #0: 0000000048f42873 (input_mutex){+.+.}, at: __input_unregister_device+0x161/0x4a0 drivers/input/input.c:2021 5 locks held by syz-executor.1/26001: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1044 Comm: khungtaskd Not tainted 5.0.0-next-20190306 #4 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 26001 Comm: syz-executor.1 Not tainted 5.0.0-next-20190306 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:io_serial_out+0x73/0x90 drivers/tty/serial/8250/8250_port.c:456 Code: 00 49 8d 7c 24 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 19 41 03 5c 24 38 44 89 e8 89 da ee <5b> 41 5c 41 5d 5d c3 e8 d1 b2 2e fe eb c0 e8 2a b3 2e fe eb e0 0f RSP: 0018:ffff888049e3f400 EFLAGS: 00000002 RAX: 000000000000005b RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff8379e2e6 RDI: ffffffff8afd5298 RBP: ffff888049e3f418 R08: ffff8880a0c0c680 R09: ffffed10093c7e7e R10: ffffed10093c7e7d R11: 0000000000000003 R12: ffffffff8afd5260 R13: 000000000000005b R14: ffffffff8afd5260 R15: 000000000000005b FS: 00007f87b6dde700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c433075000 CR3: 00000000a932a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_out include/linux/serial_core.h:278 [inline] serial8250_console_putchar+0x4e/0x60 drivers/tty/serial/8250/8250_port.c:3200 uart_console_write+0x57/0x120 drivers/tty/serial/serial_core.c:1917 serial8250_console_write+0x62b/0x9c0 drivers/tty/serial/8250/8250_port.c:3263 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:586 call_console_drivers kernel/printk/printk.c:1774 [inline] console_unlock+0xb1e/0xeb0 kernel/printk/printk.c:2452 vprintk_emit+0x280/0x6d0 kernel/printk/printk.c:1975 vprintk_default+0x28/0x30 kernel/printk/printk.c:2002 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2035 kobject_uevent_env+0x96/0x1030 lib/kobject_uevent.c:469 kobject_uevent+0x20/0x26 lib/kobject_uevent.c:638 device_add+0xb28/0x18a0 drivers/base/core.c:2105 netdev_register_kobject+0x183/0x3b0 net/core/net-sysfs.c:1746 register_netdevice+0x878/0xff0 net/core/dev.c:8711 __ip_tunnel_create+0x36b/0x530 net/ipv4/ip_tunnel.c:282 ip_tunnel_init_net+0x375/0x9e0 net/ipv4/ip_tunnel.c:1070 vti_init_net+0x2f/0x370 net/ipv4/ip_vti.c:484 ops_init+0xb6/0x410 net/core/net_namespace.c:129 setup_net+0x2c5/0x730 net/core/net_namespace.c:314 copy_net_ns+0x1d9/0x340 net/core/net_namespace.c:437 create_new_namespaces+0x400/0x7b0 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:206 ksys_unshare+0x440/0x980 kernel/fork.c:2550 __do_sys_unshare kernel/fork.c:2618 [inline] __se_sys_unshare kernel/fork.c:2616 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:2616 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458079 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f87b6dddc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000458079 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006c060000 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f87b6dde6d4 R13: 00000000004c6ddb R14: 00000000004dc598 R15: 00000000ffffffff