syzbot has bisected this bug to:
commit 6b1e6cc7855b09a0a9bfa1d9f30172ba366f161c
Author: Jason Wang <jasowang@xxxxxxxxxx>
Date: Thu Jun 23 06:04:32 2016 +0000
vhost: new device IOTLB API
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1486ad27200000
start commit: 6b1e6cc7 vhost: new device IOTLB API
git tree: upstream
final crash: https://syzkaller.appspot.com/x/report.txt?x=1686ad27200000
console output: https://syzkaller.appspot.com/x/log.txt?x=1286ad27200000
kernel config: https://syzkaller.appspot.com/x/.config?x=c94f9f0c0363db4b
dashboard link: https://syzkaller.appspot.com/bug?extid=d21e6e297322a900c128
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141db34d400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=108ef293400000
Reported-by: syzbot+d21e6e297322a900c128@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 6b1e6cc7 ("vhost: new device IOTLB API")
