------------[ cut here ]------------
kernel BUG at drivers/vhost/vhost.c:1652!
invalid opcode: 0000 [#1] SMP PTI
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 7856 Comm: syz-executor5 Not tainted 4.16.0+ #87
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:set_bit_to_user drivers/vhost/vhost.c:1650 [inline]
RIP: 0010:log_write+0x5fa/0x660 drivers/vhost/vhost.c:1676
RSP: 0018:ffff88014cd8f9c8 EFLAGS: 00010297
RAX: 0000000000000000 RBX: ffff88014a43c418 RCX: ffffffffffffffff
RDX: 0000000000000000 RSI: 000fdfdffff00001 RDI: 00000000fc400098
RBP: ffff88014cd8fa68 R08: 0000000000000000 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f40c9623700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000701514 CR3: 000000014a9ba000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vhost_update_used_flags+0x680/0x8d0 drivers/vhost/vhost.c:1723
 vhost_vq_init_access+0x173/0xa20 drivers/vhost/vhost.c:1763
 vhost_net_set_backend drivers/vhost/net.c:1166 [inline]
 vhost_net_ioctl+0x22b0/0x3480 drivers/vhost/net.c:1322
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0xaf0/0x2440 fs/ioctl.c:686
 SYSC_ioctl+0x1d2/0x260 fs/ioctl.c:701
 SyS_ioctl+0x54/0x80 fs/ioctl.c:692
 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x455979
RSP: 002b:00007f40c9622c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f40c96236d4 RCX: 0000000000455979
RDX: 0000000020d7c000 RSI: 000000004008af30 RDI: 0000000000000015
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000386 R14: 00000000006f9530 R15: 0000000000000000
Code: eb 1b 8b 7d c0 e8 f7 00 35 fa 45 85 f6 0f 89 fe fb ff ff eb 0f 4d 89 f7 e9 ed fd ff ff e8 5f 7f dd f9 eb 25 e8 58 7f dd f9 eb 3e <0f> 0b 0f 1f 40 00 eb fe 8b 7d d0 e8 c6 00 35 fa 4d 85 ff 0f 85 
RIP: set_bit_to_user drivers/vhost/vhost.c:1650 [inline] RSP: ffff88014cd8f9c8
RIP: log_write+0x5fa/0x660 drivers/vhost/vhost.c:1676 RSP: ffff88014cd8f9c8
---[ end trace 963ca71605e61750 ]---