IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready
8021q: adding VLAN 0 to HW filter on device team0
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
8021q: adding VLAN 0 to HW filter on device team0
=============================================
[ INFO: possible recursive locking detected ]
4.7.0+ #1 Not tainted
---------------------------------------------
syz-executor1/6823 is trying to acquire lock:
 (&vq->mutex){+.+...}, at: [<ffffffff84484b70>] vhost_dev_lock_vqs drivers/vhost/vhost.c:844 [inline]
 (&vq->mutex){+.+...}, at: [<ffffffff84484b70>] vhost_process_iotlb_msg+0xe0/0x9e0 drivers/vhost/vhost.c:930

but task is already holding lock:
 (&vq->mutex){+.+...}, at: [<ffffffff84484b70>] vhost_dev_lock_vqs drivers/vhost/vhost.c:844 [inline]
 (&vq->mutex){+.+...}, at: [<ffffffff84484b70>] vhost_process_iotlb_msg+0xe0/0x9e0 drivers/vhost/vhost.c:930

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&vq->mutex);
  lock(&vq->mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

1 lock held by syz-executor1/6823:
 #0:  (&vq->mutex){+.+...}, at: [<ffffffff84484b70>] vhost_dev_lock_vqs drivers/vhost/vhost.c:844 [inline]
 #0:  (&vq->mutex){+.+...}, at: [<ffffffff84484b70>] vhost_process_iotlb_msg+0xe0/0x9e0 drivers/vhost/vhost.c:930

stack backtrace:
CPU: 0 PID: 6823 Comm: syz-executor1 Not tainted 4.7.0+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
 1ffffffff0d55e4a ffff880064f2f830 ffffffff829c1956 ffffffff87e092b0
 ffff880065b68830 ffffffff87e092b0 0000000000a90548 ffff880064f2f9e0
 ffffffff81442660 ffffffff858265d0 ffff880065b68000 ffff880064f2f8a8
Call Trace:
 [<ffffffff829c1956>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff829c1956>] dump_stack+0xe6/0x120 lib/dump_stack.c:51
 [<ffffffff81442660>] print_deadlock_bug kernel/locking/lockdep.c:1723 [inline]
 [<ffffffff81442660>] check_deadlock kernel/locking/lockdep.c:1767 [inline]
 [<ffffffff81442660>] validate_chain kernel/locking/lockdep.c:2245 [inline]
 [<ffffffff81442660>] __lock_acquire+0x710/0x3cf0 kernel/locking/lockdep.c:3330
 [<ffffffff814468a6>] lock_acquire+0x196/0x480 kernel/locking/lockdep.c:3741
 [<ffffffff8581d348>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
 [<ffffffff8581d348>] mutex_lock_nested+0xa8/0xb00 kernel/locking/mutex.c:621
 [<ffffffff84484b70>] vhost_dev_lock_vqs drivers/vhost/vhost.c:844 [inline]
 [<ffffffff84484b70>] vhost_process_iotlb_msg+0xe0/0x9e0 drivers/vhost/vhost.c:930
 [<ffffffff84485552>] vhost_chr_write_iter+0xe2/0x110 drivers/vhost/vhost.c:977
 [<ffffffff84472cf0>] vhost_net_chr_write_iter+0x50/0x80 drivers/vhost/net.c:1202
 [<ffffffff8179d893>] new_sync_write fs/read_write.c:499 [inline]
 [<ffffffff8179d893>] __vfs_write+0x303/0x740 fs/read_write.c:512
 [<ffffffff8179eb87>] vfs_write+0x147/0x4a0 fs/read_write.c:560
 [<ffffffff817a234b>] SYSC_write fs/read_write.c:607 [inline]
 [<ffffffff817a234b>] SyS_write+0xcb/0x1a0 fs/read_write.c:599
 [<ffffffff85826d80>] entry_SYSCALL_64_fastpath+0x23/0xc1
kobject: 'loop2' (ffff8800688cf3a0): kobject_uevent_env
kobject: 'loop2' (ffff8800688cf3a0): fill_kobj_path: path = '/devices/virtual/block/loop2'
kobject: 'loop3' (ffff880069fab3e0): kobject_uevent_env
kobject: 'loop3' (ffff880069fab3e0): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop4' (ffff88006a0bd420): kobject_uevent_env
kobject: 'loop4' (ffff88006a0bd420): fill_kobj_path: path = '/devices/virtual/block/loop4'
kobject: 'loop0' (ffff880069325320): kobject_uevent_env
kobject: 'loop0' (ffff880069325320): fill_kobj_path: path = '/devices/virtual/block/loop0'
kobject: 'loop5' (ffff880069b53460): kobject_uevent_env
kobject: 'loop5' (ffff880069b53460): fill_kobj_path: path = '/devices/virtual/block/loop5'