Re: general protection fault in put_pid

[syzbot]

syzbot has bisected this bug to:

commit b9b8a41adeff5666b402996020b698504c927353
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date:   Mon Aug 20 08:25:33 2018 +0000

    btrfs: use after free in btrfs_quota_enable

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14155a1f200000
start commit:   f5d58277 Merge branch 'for-linus' of git://git.kernel.org/..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=16155a1f200000
console output: https://syzkaller.appspot.com/x/log.txt?x=12155a1f200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23
dashboard link: https://syzkaller.appspot.com/bug?extid=1145ec2e23165570c3ac
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16803afb400000

Reported-by: syzbot+1145ec2e23165570c3ac@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: b9b8a41adeff ("btrfs: use after free in btrfs_quota_enable")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection