[PATCH 4.16 257/272] netlabel: If PF_INET6, check sk_buff ip header version

Greg Kroah-Hartman
2018-05-28T11:15:57Z

From: Richard Haines <richard_c_haines@btinternet.com>

[ Upstream commit 213d7f94775322ba44e0bbb55ec6946e9de88cea ]

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.

Signed-off-by: Richard Haines <richard_c_haines@btinternet.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/netlabel/netlabel_unlabeled.c | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -1472,6 +1472,16 @@ int netlbl_unlabel_getattr(const struct
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;