From: Daniel Borkmann <dborkman@redhat.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>,
Hannes Frederic Sowa <hannes@stressinduktion.org>,
Neil Horman <nhorman@tuxdriver.com>,
Jesper Dangaard Brouer <brouer@redhat.com>,
netdev <netdev@vger.kernel.org>, Guy Harris <guy@alum.mit.edu>
Subject: Re: [PATCH v1 net] packet: handle too big packets for PACKET_V3
Date: Mon, 18 Aug 2014 17:39:02 +0200 [thread overview]
Message-ID: <53F21E16.1090706@redhat.com> (raw)
In-Reply-To: <1408119364.6804.89.camel@edumazet-glaptop2.roam.corp.google.com>
On 08/15/2014 06:16 PM, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> af_packet can currently overwrite kernel memory by out of bound
> accesses, because it assumed a [new] block can always hold one frame.
>
> This is not generally the case, even if most existing tools do it right.
>
> This patch clamps too long frames as API permits, and issue a one time
> error on syslog.
>
> [ 394.357639] tpacket_rcv: packet too big, clamped from 5042 to 3966. macoff=82
>
> In this example, packet header tp_snaplen was set to 3966,
> and tp_len was set to 5042 (skb->len)
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Acked-by: Daniel Borkmann <dborkman@redhat.com>
This looks good to me, thanks Eric!
[ Truly dislike the TPACKET_V3 code ... :/ ]
next prev parent reply other threads:[~2014-08-18 15:39 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-15 0:09 [RFC] packet: handle too big packets for PACKET_V3 Eric Dumazet
2014-08-15 0:36 ` Neil Horman
2014-08-15 0:43 ` Hannes Frederic Sowa
2014-08-15 0:50 ` Hannes Frederic Sowa
2014-08-15 0:56 ` Eric Dumazet
2014-08-15 10:19 ` Neil Horman
2014-08-15 0:54 ` Eric Dumazet
2014-08-15 1:04 ` Hannes Frederic Sowa
2014-08-15 2:01 ` Eric Dumazet
2014-08-15 2:08 ` Hannes Frederic Sowa
2014-08-15 5:02 ` Guy Harris
2014-08-15 16:00 ` Eric Dumazet
2014-08-15 16:16 ` [PATCH v1 net] " Eric Dumazet
2014-08-18 15:39 ` Daniel Borkmann [this message]
2014-08-18 17:08 ` Neil Horman
2014-08-21 23:45 ` David Miller
2014-08-15 4:54 ` [RFC] " Guy Harris
2014-08-15 11:37 ` Hannes Frederic Sowa
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