linux-kernel - Re: [PATCH] kernel/groups.c: Minor bugfix for overflow in binary search

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: <CA+55aFz8AbSOZFp-nnvTTFkH5p1vgHfnu9KjsEKwUUOJH1WyUA@mail.gmail.com>
Date:	Thu, 29 Sep 2011 22:44:16 -0700
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	Josh Zimmerman <jzimmerm@...rew.cmu.edu>
Cc:	akpm@...ux-foundation.org, serge.hallyn@...onical.com,
	ebiederm@...ssion.com, dhowells@...hat.com, daniel.lezcano@...e.fr,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] kernel/groups.c: Minor bugfix for overflow in binary search

On Thu, Sep 29, 2011 at 9:39 PM, Josh Zimmerman <jzimmerm@...rew.cmu.edu> wrote:
>
> Fixed possible unsigned int overflow bug. (2 + 2^(32) - 1)/2 results in overflow; 2 + (2^(32)-1-2)/2 does not.

We can't have that many groups anyway, so the overflow is pretty theoretical.

The max should be NGROUPS_MAX, afaik (65536) and other places have
lower limits (ie sunrpc/nfs). And if some place doesn't limit it
correctly, we have bigger problems than this (the whole allocation and
CPU use issues)

            Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/