From: Jarek Poplawski <jarkao2@gmail.com>
To: Roel Kluin <roel.kluin@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] [IPV4]: Buffer overflow
Date: Thu, 30 Jul 2009 00:02:39 +0200 [thread overview]
Message-ID: <4A70C6FF.9060302@gmail.com> (raw)
In-Reply-To: <4A702A02.30509@gmail.com>
Roel Kluin wrote, On 07/29/2009 12:52 PM:
> If arp_format_neigh_entry() can be called with n->dev->addr_len == 0, then a
> write to hbuffer[-1] occurs.
>
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
> ---
> Found with Parfait, http://research.sun.com/projects/parfait/
>
> It's not clear whether this can happen or not.
>
> diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
> index c29d75d..252336f 100644
> --- a/net/ipv4/arp.c
> +++ b/net/ipv4/arp.c
> @@ -1304,7 +1304,8 @@ static void arp_format_neigh_entry(struct seq_file *seq,
> hbuffer[k++] = hex_asc_lo(n->ha[j]);
> hbuffer[k++] = ':';
> }
> - hbuffer[--k] = 0;
> + if (k != 0)
> + hbuffer[--k] = 0;
I guess for k == 0 we need hbuffer[0] = 0 too.
Jarek P.
> #if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
> }
> #endif
> --
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>
next prev parent reply other threads:[~2009-07-29 22:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-29 10:52 [PATCH] [IPV4]: Buffer overflow Roel Kluin
2009-07-29 22:02 ` Jarek Poplawski [this message]
2009-07-30 9:46 ` Roel Kluin
2009-07-30 20:28 ` David Miller
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