syzbot has bisected this bug to: commit ab42f35d9cb5ac49b5a2a11f940e74f58f207280 Author: Ming Lei <ming.lei@xxxxxxxxxx> Date: Fri May 26 11:53:19 2017 +0000 blk-mq: merge bio into sw queue before plugging bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1681996f200000 start commit: ab42f35d blk-mq: merge bio into sw queue before plugging git tree: upstream final crash: https://syzkaller.appspot.com/x/report.txt?x=1581996f200000 console output: https://syzkaller.appspot.com/x/log.txt?x=1181996f200000 kernel config: https://syzkaller.appspot.com/x/.config?x=5e7dc790609552d7 dashboard link: https://syzkaller.appspot.com/bug?extid=b92e4f1472a54e1c7dec userspace arch: amd64 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=107db700c00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12304827400000 Reported-by: syzbot+b92e4f1472a54e1c7dec@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: ab42f35d ("blk-mq: merge bio into sw queue before plugging")