On Mon, 2023-11-06 at 17:53 -0500, Paul Moore wrote:

On Mon, Nov 6, 2023 at 3:34 AM syzbot
[off-list ref] wrote:

quoted

syzbot has bisected this issue to:

commit d82dcd9e21b77d338dc4875f3d4111f0db314a7c
Author: Roberto Sassu [off-list ref]
Date:   Fri Mar 31 12:32:18 2023 +0000

    reiserfs: Add security prefix to xattr name in reiserfs_security_write()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14d0b787680000
start commit:   90b0c2b2edd1 Merge tag 'pinctrl-v6.7-1' of git://git.kerne..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=16d0b787680000
console output: https://syzkaller.appspot.com/x/log.txt?x=12d0b787680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=93ac5233c138249e
dashboard link: https://syzkaller.appspot.com/bug?extid=c319bb5b1014113a92cf
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=113f3717680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=154985ef680000

Reported-by: syzbot+c319bb5b1014113a92cf@syzkaller.appspotmail.com
Fixes: d82dcd9e21b7 ("reiserfs: Add security prefix to xattr name in reiserfs_security_write()")

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

Hi Roberto,

I know you were looking at this over the summer[1], did you ever find
a resolution to this?  If not, what do you think of just dropping
security xattr support on reiserfs?  Normally that wouldn't be
something we could consider, but given the likelihood that this hadn't
been working in *years* (if ever), and reiserfs is deprecated, I think
this is a viable option if there isn't an obvious fix.

[1] https://lore.kernel.org/linux-security-module/CAHC9VhTM0a7jnhxpCyonepcfWbnG-OJbbLpjQi68gL2GVnKSRg@mail.gmail.com/ (local)

Hi Paul

at the time, I did some investigation and came with a patch that
(likely) solves some of the problems:

https://lore.kernel.org/linux-fsdevel/4aa799a0b87d4e2ecf3fa74079402074dc42b3c5.camel@huaweicloud.com/#t (local)

I did a more advanced patch (to be validated), trying to fix the root
cause:

https://lore.kernel.org/linux-fsdevel/ffde7908-be73-cc56-2646-72f4f94cb51b@huaweicloud.com/ (local)

However, Jeff Mahoney (that did a lot of work in this area) suggested
that maybe we should not try invasive changes, as anyway reiserfs will
be removed from the kernel in 2025.

It wouldn't be a problem to move the first patch forward.

Roberto