linux-kernel - Re: [PATCH] kernel/sysctl.c: fix out of bounds access in fs.file-max

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190403155108.GI22763@bombadil.infradead.org>
Date:   Wed, 3 Apr 2019 08:51:08 -0700
From:   Matthew Wilcox <willy@...radead.org>
To:     Matteo Croce <mcroce@...hat.com>
Cc:     Christian Brauner <christian@...uner.io>,
        linux-fsdevel@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>,
        Luis Chamberlain <mcgrof@...nel.org>,
        Kees Cook <keescook@...omium.org>,
        Zev Weiss <zev@...ilderbeest.net>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH] kernel/sysctl.c: fix out of bounds access in fs.file-max

On Wed, Apr 03, 2019 at 05:24:26PM +0200, Matteo Croce wrote:
> On Wed, Apr 3, 2019 at 4:02 PM Christian Brauner <christian@...uner.io> wrote:
> > Yeah, maybe but it still feels cleaner and more obvious to just add:
> >
> > static long long_zero;
> >
> > given that most callers actually seem to want an (unsigned) int.
> >
> > I don't have a strong opinion though so if others feel that it's just a
> > waste of space consider it acked.
> >
> 
> Well, given that the value is zero, in this expectional case we could
> avoid duplicating the symbol and save 4 bytes.
> What the maintainers think?

If we care about saving four bytes, we could just pass the address of
ZERO_PAGE(0).