[NETFILTER]: xt_pkttype: Add explicit check for IPv4

In the PACKET_LOOPBACK case, the skb data was always interpreted as
IPv4, but that is not valid for IPv6, obviously. Fix this by adding an
extra condition to check for AF_INET.

Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/netfilter/xt_pkttype.c b/net/netfilter/xt_pkttype.c
index 276244902ab5..080f3246eee7 100644
--- a/net/netfilter/xt_pkttype.c
+++ b/net/netfilter/xt_pkttype.c
@@ -31,7 +31,8 @@ pkttype_mt(const struct sk_buff *skb, const struct net_device *in,
         const struct xt_pkttype_info *info = matchinfo;
 
         if (skb->pkt_type == PACKET_LOOPBACK)
-                type = ipv4_is_multicast(ip_hdr(skb)->daddr)
+                type = match->family == AF_INET &&
+                       ipv4_is_multicast(ip_hdr(skb)->daddr)
                         ? PACKET_MULTICAST
                         : PACKET_BROADCAST;
         else