net: flow_dissector: fail on evil iph->ihl

[mirror_ubuntu-bionic-kernel.git] / net / core / flow_dissector.c

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 8d7d0dd72db211e23b5bcffd16f7600841841598..143b6fdb9647dae2d9c9f65d1a72e56bce1a1cc5 100644 (file)
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -40,7 +40,7 @@ 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))