netlabel: If PF_INET6, check sk_buff ip header version

Richard Haines · pcmoore · commit 213d7f947753 · 2018-02-14T14:01:41.000-05:00
When resolving a fallback label, check the sk_buff version as it
is possible (e.g. SCTP) to have family = PF_INET6 while
receiving ip_hdr(skb)-&gt;version = 4.

Signed-off-by: Richard Haines &lt;richard_c_haines@btinternet.com&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt;
Signed-off-by: Paul Moore &lt;paul@paul-moore.com&gt;
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
@@ -1472,6 +1472,16 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb,
 		iface = rcu_dereference(netlbl_unlhsh_def);
 	if (iface == NULL || !iface->valid)
 		goto unlabel_getattr_nolabel;
+
+#if IS_ENABLED(CONFIG_IPV6)
+	/* When resolving a fallback label, check the sk_buff version as
+	 * it is possible (e.g. SCTP) to have family = PF_INET6 while
+	 * receiving ip_hdr(skb)->version = 4.
+	 */
+	if (family == PF_INET6 && ip_hdr(skb)->version == 4)
+		family = PF_INET;
+#endif /* IPv6 */
+
 	switch (family) {
 	case PF_INET: {
 		struct iphdr *hdr4;
