Re: [syzbot] [bcachefs?] UBSAN: shift-out-of-bounds in validate_sb_layout

[syzbot]

syzbot has bisected this issue to:

commit 03ef80b469d5d83530ce1ce15be78a40e5300f9b
Author: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Date:   Sat Sep 23 22:41:51 2023 +0000

    bcachefs: Ignore unknown mount options

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=12accc30580000
start commit:   c2ee9f594da8 KVM: selftests: Fix build on on non-x86 archi..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=11accc30580000
console output: https://syzkaller.appspot.com/x/log.txt?x=16accc30580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=41330fd2db03893d
dashboard link: https://syzkaller.appspot.com/bug?extid=089fad5a3a5e77825426
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=109dd640580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14f288a7980000

Reported-by: syzbot+089fad5a3a5e77825426@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 03ef80b469d5 ("bcachefs: Ignore unknown mount options")

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