From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Florian Westphal <fw@strlen.de>
Cc: syzkaller-bugs@googlegroups.com, netdev@vger.kernel.org,
bridge@lists.linux-foundation.org,
netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nf] netfilter: bridge: ebt_among: add missing match size checks
Date: Sun, 25 Feb 2018 20:04:45 +0100 [thread overview]
Message-ID: <20180225190445.ixdsjfe6ri57nlpe@salvia> (raw)
In-Reply-To: <20180219020145.30899-1-fw@strlen.de>
On Mon, Feb 19, 2018 at 03:01:45AM +0100, Florian Westphal wrote:
> ebt_among is special, it has a dynamic match size and is exempt
> from the central size checks.
>
> Therefore it must check that the size of the match structure
> provided from userspace is sane by making sure em->match_size
> is at least the minimum size of the expected structure.
>
> The module has such a check, but its only done after accessing
> a structure that might be out of bounds.
>
> tested with: ebtables -A INPUT ... \
> --among-dst fe:fe:fe:fe:fe:fe
> --among-dst fe:fe:fe:fe:fe:fe --among-src fe:fe:fe:fe:ff:f,fe:fe:fe:fe:fe:fb,fe:fe:fe:fe:fc:fd,fe:fe:fe:fe:fe:fd,fe:fe:fe:fe:fe:fe
> --among-src fe:fe:fe:fe:ff:f,fe:fe:fe:fe:fe:fa,fe:fe:fe:fe:fe:fd,fe:fe:fe:fe:fe:fe,fe:fe:fe:fe:fe:fe
Applied, thanks Florian.
prev parent reply other threads:[~2018-02-25 19:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-18 22:59 BUG: unable to handle kernel paging request in ebt_among_mt_check syzbot
2018-02-19 2:01 ` [PATCH nf] netfilter: bridge: ebt_among: add missing match size checks Florian Westphal
2018-02-25 19:04 ` Pablo Neira Ayuso [this message]
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