[IGMP/MLD]: Validate filter size against optlen.

net/ipv4/ip_sockglue.c

@@ -631,6 +631,11 @@ int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int opt
 				kfree(msf);
 				break;
 			}
+			if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
+				kfree(msf);
+				err = -EINVAL;
+				break;
+			}
 			err = ip_mc_msfilter(sk, msf, 0);
 			kfree(msf);
 			break;

net/ipv6/ipv6_sockglue.c

@@ -450,6 +450,11 @@ int ipv6_setsockopt(struct sock *sk, int level, int optname, char *optval,
 			kfree(gsf);
 			break;
 		}
+		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
+			kfree(gsf);
+			retv = -EINVAL;
+			break;
+		}
 		retv = ip6_mc_msfilter(sk, gsf);
 		kfree(gsf);