INFO: task syz-executor.0:7737 blocked for more than 140 seconds. Not tainted 5.0.0-rc5-next-20190208 #31 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29392 7737 7434 0x00000004 Call Trace: context_switch kernel/sched/core.c:2847 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3488 schedule+0x92/0x180 kernel/sched/core.c:3532 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3590 __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_init_device_iotlb+0x124/0x280 drivers/vhost/vhost.c:1607 vhost_net_set_features drivers/vhost/net.c:1675 [inline] vhost_net_ioctl+0x10be/0x1900 drivers/vhost/net.c:1740 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457e39 Code: Bad RIP value. RSP: 002b:00007f6a17a62c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39 RDX: 0000000020000080 RSI: 000000004008af00 RDI: 0000000000000005 RBP: 000000000073c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6a17a636d4 R13: 00000000004c26bc R14: 00000000004d5068 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1041: #0: 00000000d57f4ac2 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4374 1 lock held by rsyslogd/7284: #0: 00000000c9804570 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:796 2 locks held by getty/7399: #0: 00000000e60ec4bd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000fa504051 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7400: #0: 000000009ddc0c60 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000bd96cdcb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7401: #0: 00000000bfebebba (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009096c1b0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7402: #0: 0000000019df15e3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d4178077 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7403: #0: 0000000062fb1360 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007591474f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7404: #0: 00000000dbe9c525 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005465c622 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7405: #0: 000000006c633475 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000067438cbd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/7737: #0: 0000000078affb5a (&dev->mutex#4){+.+.}, at: vhost_net_set_features drivers/vhost/net.c:1669 [inline] #0: 0000000078affb5a (&dev->mutex#4){+.+.}, at: vhost_net_ioctl+0x1cc/0x1900 drivers/vhost/net.c:1740 #1: 0000000085b2637b (&vq->mutex){+.+.}, at: vhost_init_device_iotlb+0x124/0x280 drivers/vhost/vhost.c:1607 1 lock held by vhost-7702/7715: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.0.0-rc5-next-20190208 #31 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+0x9df/0xee0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: