net: lwtunnel: Handle lwtunnel_fill_encap failure

BugLink: http://bugs.launchpad.net/bugs/1662507

[ Upstream commit ea7a8085 ]

Handle failure in lwtunnel_fill_encap adding attributes to skb.

Fixes: 571e7226 ("ipv4: support for fib route lwtunnel encap attributes")
Fixes: 19e42e45 ("ipv6: support for fib route lwtunnel encap attributes")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

net/ipv4/fib_semantics.c

@@ -1277,8 +1277,9 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 		    nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid))
 			goto nla_put_failure;
 #endif
-		if (fi->fib_nh->nh_lwtstate)
-			lwtunnel_fill_encap(skb, fi->fib_nh->nh_lwtstate);
+		if (fi->fib_nh->nh_lwtstate &&
+		    lwtunnel_fill_encap(skb, fi->fib_nh->nh_lwtstate) < 0)
+			goto nla_put_failure;
 	}
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	if (fi->fib_nhs > 1) {
@@ -1314,8 +1315,10 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
 			    nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
 				goto nla_put_failure;
 #endif
-			if (nh->nh_lwtstate)
-				lwtunnel_fill_encap(skb, nh->nh_lwtstate);
+			if (nh->nh_lwtstate &&
+			    lwtunnel_fill_encap(skb, nh->nh_lwtstate) < 0)
+				goto nla_put_failure;
+
 			/* length of rtnetlink header + attributes */
 			rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
 		} endfor_nexthops(fi);

net/ipv6/route.c

@@ -3196,7 +3196,8 @@ static int rt6_fill_node(struct net *net,
 	if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt->rt6i_flags)))
 		goto nla_put_failure;
 
-	lwtunnel_fill_encap(skb, rt->dst.lwtstate);
+	if (lwtunnel_fill_encap(skb, rt->dst.lwtstate) < 0)
+		goto nla_put_failure;
 
 	nlmsg_end(skb, nlh);
 	return 0;