netfilter: ipset: add missing range check in bitmap_ip_uadt

When tb[IPSET_ATTR_IP_TO] is not present but tb[IPSET_ATTR_CIDR] exists,
the values of ip and ip_to are slightly swapped. Therefore, the range check
for ip should be done later, but this part is missing and it seems that the
vulnerability occurs.

So we should add missing range checks and remove unnecessary range checks.

Cc: <[email protected]>
Reported-by: [email protected]
Fixes: 72205fc ("netfilter: ipset: bitmap:ip set type support")
Signed-off-by: Jeongjun Park <[email protected]>
Acked-by: Jozsef Kadlecsik <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>

Author: name2965

net/netfilter/ipset/ip_set_bitmap_ip.c

@@ -163,11 +163,8 @@ bitmap_ip_uadt(struct ip_set *set, struct nlattr *tb[],
 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP_TO], &ip_to);
 		if (ret)
 			return ret;
-		if (ip > ip_to) {
+		if (ip > ip_to)
 			swap(ip, ip_to);
-			if (ip < map->first_ip)
-				return -IPSET_ERR_BITMAP_RANGE;
-		}
 	} else if (tb[IPSET_ATTR_CIDR]) {
 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
 
@@ -178,7 +175,7 @@ bitmap_ip_uadt(struct ip_set *set, struct nlattr *tb[],
 		ip_to = ip;
 	}
 
-	if (ip_to > map->last_ip)
+	if (ip < map->first_ip || ip_to > map->last_ip)
 		return -IPSET_ERR_BITMAP_RANGE;
 
 	for (; !before(ip_to, ip); ip += map->hosts) {