[IPV6] ADDRCONF: Check payload length for IFA_LOCAL attribute in RTM_{ADD,DEL}MSG message

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

net/ipv6/addrconf.c

@@ -2853,7 +2853,8 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 		pfx = RTA_DATA(rta[IFA_ADDRESS-1]);
 	}
 	if (rta[IFA_LOCAL-1]) {
-		if (pfx && memcmp(pfx, RTA_DATA(rta[IFA_LOCAL-1]), sizeof(*pfx)))
+		if (RTA_PAYLOAD(rta[IFA_LOCAL-1]) < sizeof(*pfx) ||
+		    (pfx && memcmp(pfx, RTA_DATA(rta[IFA_LOCAL-1]), sizeof(*pfx))))
 			return -EINVAL;
 		pfx = RTA_DATA(rta[IFA_LOCAL-1]);
 	}
@@ -2877,7 +2878,8 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 		pfx = RTA_DATA(rta[IFA_ADDRESS-1]);
 	}
 	if (rta[IFA_LOCAL-1]) {
-		if (pfx && memcmp(pfx, RTA_DATA(rta[IFA_LOCAL-1]), sizeof(*pfx)))
+		if (RTA_PAYLOAD(rta[IFA_LOCAL-1]) < sizeof(*pfx) ||
+		    (pfx && memcmp(pfx, RTA_DATA(rta[IFA_LOCAL-1]), sizeof(*pfx))))
 			return -EINVAL;
 		pfx = RTA_DATA(rta[IFA_LOCAL-1]);
 	}