Re: KASAN: use-after-free Read in bdev_del_partition

[syzbot]

syzbot has bisected this issue to:

commit cddae808aeb77e5c29d22a8e0dfbdaed413f9e04
Author: Christoph Hellwig <hch@xxxxxx>
Date:   Tue Apr 14 07:28:54 2020 +0000

    block: pass a hd_struct to delete_partition

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17fa7656900000
start commit:   dcc5c6f0 Merge tag 'x86-urgent-2020-08-30' of git://git.ke..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=14067656900000
console output: https://syzkaller.appspot.com/x/log.txt?x=10067656900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=891ca5711a9f1650
dashboard link: https://syzkaller.appspot.com/bug?extid=6448f3c229bc52b82f69
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=154e2285900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16f6e915900000

Reported-by: syzbot+6448f3c229bc52b82f69@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: cddae808aeb7 ("block: pass a hd_struct to delete_partition")

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