syzbot has bisected this bug to:
commit bfe4037e722ec672c9dafd5730d9132afeeb76e9
Author: Christoph Hellwig <hch@xxxxxx>
Date: Mon Jul 16 07:08:20 2018 +0000
aio: implement IOCB_CMD_POLL
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=108886bd200000
start commit: bfe4037e aio: implement IOCB_CMD_POLL
git tree: upstream
final crash: https://syzkaller.appspot.com/x/report.txt?x=128886bd200000
console output: https://syzkaller.appspot.com/x/log.txt?x=148886bd200000
kernel config: https://syzkaller.appspot.com/x/.config?x=2e0064f906afee10
dashboard link: https://syzkaller.appspot.com/bug?extid=a3accb352f9c22041cfa
userspace arch: amd64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=156479f8c00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=128c75c4c00000
Reported-by: syzbot+a3accb352f9c22041cfa@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: bfe4037e ("aio: implement IOCB_CMD_POLL")
