From: David Miller <davem@davemloft.net>
To: dborkman@redhat.com
Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com
Subject: Re: [PATCH net] net: ipv6: tcp: fix potential use after free in tcp_v6_do_rcv
Date: Wed, 04 Sep 2013 14:57:04 -0400 (EDT) [thread overview]
Message-ID: <20130904.145704.1474150306960456668.davem@davemloft.net> (raw)
In-Reply-To: <1378229352-9779-1-git-send-email-dborkman@redhat.com>
From: Daniel Borkmann <dborkman@redhat.com>
Date: Tue, 3 Sep 2013 19:29:12 +0200
> In tcp_v6_do_rcv() code, when processing pkt options, we soley work
> on our skb clone opt_skb that we've created earlier before entering
> tcp_rcv_established() on our way. However, only in condition ...
>
> if (np->rxopt.bits.rxtclass)
> np->rcv_tclass = ipv6_get_dsfield(ipv6_hdr(skb));
>
> ... we work on skb itself. As we extract every other information out
> of opt_skb in ipv6_pktoptions path, this seems wrong, since skb can
> already be released by tcp_rcv_established() earlier on. When we try
> to access it in ipv6_hdr(), we will dereference freed skb.
>
> Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
> Cc: Eric Dumazet <eric.dumazet@gmail.com>
Applied.
prev parent reply other threads:[~2013-09-04 18:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-03 17:29 [PATCH net] net: ipv6: tcp: fix potential use after free in tcp_v6_do_rcv Daniel Borkmann
2013-09-03 17:48 ` Eric Dumazet
2013-09-03 19:46 ` Jean Sacren
2013-09-03 20:35 ` Eric Dumazet
2013-09-03 21:59 ` Jean Sacren
2013-09-03 22:25 ` Daniel Borkmann
2013-09-03 22:29 ` Eric Dumazet
2013-09-04 0:51 ` Jean Sacren
2013-09-04 6:26 ` Jiri Benc
2013-09-04 18:57 ` David Miller [this message]
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