| From | Kamal Mostafa <> | Subject | [PATCH 3.8 006/152] net: flow_dissector: fail on evil iph->ihl | Date | Fri, 6 Dec 2013 15:08:50 -0800 |
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3.8.13.14 -stable review patch. If anyone has any objections, please let me know.
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From: Jason Wang <jasowang@redhat.com>
[ Upstream commit 6f092343855a71e03b8d209815d8c45bf3a27fcd ]
We don't validate iph->ihl which may lead a dead loop if we meet a IPIP skb whose iph->ihl is zero. Fix this by failing immediately when iph->ihl is evil (less than 5).
This issue were introduced by commit ec5efe7946280d1e84603389a1030ccec0a767ae (rps: support IPIP encapsulation).
Cc: Eric Dumazet <edumazet@google.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- net/core/flow_dissector.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 744b3ad..e2df3a9 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -36,7 +36,7 @@ again: struct iphdr _iph; ip: iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); - if (!iph) + if (!iph || iph->ihl < 5) return false; if (ip_is_fragment(iph)) -- 1.8.3.2
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