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| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2013-06-11 01:51:31 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2013-06-11 01:55:07 +0200 |
| commit | ed82c437320c48a4032492f4a55a7e2c934158b6 (patch) | |
| tree | f86328e2d8d222989322f0a9d65e04218f3e531f | |
| parent | a8241c63517ec0b900695daa9003cddc41c536a1 (diff) | |
| download | blackbird-op-linux-ed82c437320c48a4032492f4a55a7e2c934158b6.tar.gz blackbird-op-linux-ed82c437320c48a4032492f4a55a7e2c934158b6.zip | |
netfilter: xt_TCPOPTSTRIP: don't use tcp_hdr()
In (bc6bcb5 netfilter: xt_TCPOPTSTRIP: fix possible mangling beyond
packet boundary), the use of tcp_hdr was introduced. However, we
cannot assume that skb->transport_header is set for non-local packets.
Cc: Florian Westphal <fw@strlen.de>
Reported-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/netfilter/xt_TCPOPTSTRIP.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/netfilter/xt_TCPOPTSTRIP.c b/net/netfilter/xt_TCPOPTSTRIP.c index 1eb1a44bfd3d..b68fa191710f 100644 --- a/net/netfilter/xt_TCPOPTSTRIP.c +++ b/net/netfilter/xt_TCPOPTSTRIP.c @@ -48,11 +48,13 @@ tcpoptstrip_mangle_packet(struct sk_buff *skb, return NF_DROP; len = skb->len - tcphoff; - if (len < (int)sizeof(struct tcphdr) || - tcp_hdr(skb)->doff * 4 > len) + if (len < (int)sizeof(struct tcphdr)) return NF_DROP; tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff); + if (tcph->doff * 4 > len) + return NF_DROP; + opt = (u_int8_t *)tcph; /* |
