netdev - Re: [PATCH net] ipv4: better IP_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] [day] [month] [year] [list]

Message-Id: <20170816.162925.2199453201191784671.davem@davemloft.net>
Date:   Wed, 16 Aug 2017 16:29:25 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     eric.dumazet@...il.com
Cc:     netdev@...r.kernel.org
Subject: Re: [PATCH net] ipv4: better IP_MAX_MTU enforcement

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Wed, 16 Aug 2017 11:09:12 -0700

> From: Eric Dumazet <edumazet@...gle.com>
> 
> While working on yet another syzkaller report, I found
> that our IP_MAX_MTU enforcements were not properly done.
> 
> gcc seems to reload dev->mtu for min(dev->mtu, IP_MAX_MTU), and
> final result can be bigger than IP_MAX_MTU :/
> 
> This is a problem because device mtu can be changed on other cpus or
> threads.
> 
> While this patch does not fix the issue I am working on, it is
> probably worth addressing it.
> 
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>

Also applied and queued up for -stable.

Thanks.