netfilter: ipset: Limit the maximal range of consecutive elements to add/delete

The range size of consecutive elements were not limited. Thus one could
define a huge range which may result soft lockup errors due to the long
execution time. Now the range size is limited to 2^20 entries.
Reported-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/linux/netfilter/ipset/ip_set.h

@@ -196,6 +196,9 @@ struct ip_set_region {
 	u32 elements;		/* Number of elements vs timeout */
 };
 
+/* Max range where every element is added/deleted in one step */
+#define IPSET_MAX_RANGE		(1<<20)
+
 /* The max revision number supported by any set type + 1 */
 #define IPSET_REVISION_MAX	9
 

net/netfilter/ipset/ip_set_hash_ip.c

@@ -132,8 +132,11 @@ hash_ip4_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) {
+			if (ip_to == 0)
+				return -IPSET_ERR_HASH_ELEM;
 			swap(ip, ip_to);
+		}
 	} else if (tb[IPSET_ATTR_CIDR]) {
 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
 
@@ -144,6 +147,10 @@ hash_ip4_uadt(struct ip_set *set, struct nlattr *tb[],
 
 	hosts = h->netmask == 32 ? 1 : 2 << (32 - h->netmask - 1);
 
+	/* 64bit division is not allowed on 32bit */
+	if (((u64)ip_to - ip + 1) >> (32 - h->netmask) > IPSET_MAX_RANGE)
+		return -ERANGE;
+
 	if (retried) {
 		ip = ntohl(h->next.ip);
 		e.ip = htonl(ip);

net/netfilter/ipset/ip_set_hash_ipmark.c

@@ -121,6 +121,8 @@ hash_ipmark4_uadt(struct ip_set *set, struct nlattr *tb[],
 
 	e.mark = ntohl(nla_get_be32(tb[IPSET_ATTR_MARK]));
 	e.mark &= h->markmask;
+	if (e.mark == 0 && e.ip == 0)
+		return -IPSET_ERR_HASH_ELEM;
 
 	if (adt == IPSET_TEST ||
 	    !(tb[IPSET_ATTR_IP_TO] || tb[IPSET_ATTR_CIDR])) {
@@ -133,8 +135,11 @@ hash_ipmark4_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) {
+			if (e.mark == 0 && ip_to == 0)
+				return -IPSET_ERR_HASH_ELEM;
 			swap(ip, ip_to);
+		}
 	} else if (tb[IPSET_ATTR_CIDR]) {
 		u8 cidr = nla_get_u8(tb[IPSET_ATTR_CIDR]);
 
@@ -143,6 +148,9 @@ hash_ipmark4_uadt(struct ip_set *set, struct nlattr *tb[],
 		ip_set_mask_from_to(ip, ip_to, cidr);
 	}
 
+	if (((u64)ip_to - ip + 1) > IPSET_MAX_RANGE)
+		return -ERANGE;
+
 	if (retried)
 		ip = ntohl(h->next.ip);
 	for (; ip <= ip_to; ip++) {

net/netfilter/ipset/ip_set_hash_ipport.c

@@ -173,6 +173,9 @@ hash_ipport4_uadt(struct ip_set *set, struct nlattr *tb[],
 			swap(port, port_to);
 	}
 
+	if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
+		return -ERANGE;
+
 	if (retried)
 		ip = ntohl(h->next.ip);
 	for (; ip <= ip_to; ip++) {

net/netfilter/ipset/ip_set_hash_ipportip.c

@@ -180,6 +180,9 @@ hash_ipportip4_uadt(struct ip_set *set, struct nlattr *tb[],
 			swap(port, port_to);
 	}
 
+	if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
+		return -ERANGE;
+
 	if (retried)
 		ip = ntohl(h->next.ip);
 	for (; ip <= ip_to; ip++) {

net/netfilter/ipset/ip_set_hash_ipportnet.c

@@ -253,6 +253,9 @@ hash_ipportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
 			swap(port, port_to);
 	}
 
+	if (((u64)ip_to - ip + 1)*(port_to - port + 1) > IPSET_MAX_RANGE)
+		return -ERANGE;
+
 	ip2_to = ip2_from;
 	if (tb[IPSET_ATTR_IP2_TO]) {
 		ret = ip_set_get_hostipaddr4(tb[IPSET_ATTR_IP2_TO], &ip2_to);

net/netfilter/ipset/ip_set_hash_net.c

@@ -140,7 +140,7 @@ hash_net4_uadt(struct ip_set *set, struct nlattr *tb[],
 	ipset_adtfn adtfn = set->variant->adt[adt];
 	struct hash_net4_elem e = { .cidr = HOST_MASK };
 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
-	u32 ip = 0, ip_to = 0;
+	u32 ip = 0, ip_to = 0, ipn, n = 0;
 	int ret;
 
 	if (tb[IPSET_ATTR_LINENO])
@@ -188,6 +188,15 @@ hash_net4_uadt(struct ip_set *set, struct nlattr *tb[],
 		if (ip + UINT_MAX == ip_to)
 			return -IPSET_ERR_HASH_RANGE;
 	}
+	ipn = ip;
+	do {
+		ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr);
+		n++;
+	} while (ipn++ < ip_to);
+
+	if (n > IPSET_MAX_RANGE)
+		return -ERANGE;
+
 	if (retried)
 		ip = ntohl(h->next.ip);
 	do {

net/netfilter/ipset/ip_set_hash_netiface.c

@@ -202,7 +202,7 @@ hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
 	ipset_adtfn adtfn = set->variant->adt[adt];
 	struct hash_netiface4_elem e = { .cidr = HOST_MASK, .elem = 1 };
 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
-	u32 ip = 0, ip_to = 0;
+	u32 ip = 0, ip_to = 0, ipn, n = 0;
 	int ret;
 
 	if (tb[IPSET_ATTR_LINENO])
@@ -256,6 +256,14 @@ hash_netiface4_uadt(struct ip_set *set, struct nlattr *tb[],
 	} else {
 		ip_set_mask_from_to(ip, ip_to, e.cidr);
 	}
+	ipn = ip;
+	do {
+		ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr);
+		n++;
+	} while (ipn++ < ip_to);
+
+	if (n > IPSET_MAX_RANGE)
+		return -ERANGE;
 
 	if (retried)
 		ip = ntohl(h->next.ip);

net/netfilter/ipset/ip_set_hash_netnet.c

@@ -168,7 +168,8 @@ hash_netnet4_uadt(struct ip_set *set, struct nlattr *tb[],
 	struct hash_netnet4_elem e = { };
 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
 	u32 ip = 0, ip_to = 0;
-	u32 ip2 = 0, ip2_from = 0, ip2_to = 0;
+	u32 ip2 = 0, ip2_from = 0, ip2_to = 0, ipn;
+	u64 n = 0, m = 0;
 	int ret;
 
 	if (tb[IPSET_ATTR_LINENO])
@@ -244,6 +245,19 @@ hash_netnet4_uadt(struct ip_set *set, struct nlattr *tb[],
 	} else {
 		ip_set_mask_from_to(ip2_from, ip2_to, e.cidr[1]);
 	}
+	ipn = ip;
+	do {
+		ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr[0]);
+		n++;
+	} while (ipn++ < ip_to);
+	ipn = ip2_from;
+	do {
+		ipn = ip_set_range_to_cidr(ipn, ip2_to, &e.cidr[1]);
+		m++;
+	} while (ipn++ < ip2_to);
+
+	if (n*m > IPSET_MAX_RANGE)
+		return -ERANGE;
 
 	if (retried) {
 		ip = ntohl(h->next.ip[0]);

net/netfilter/ipset/ip_set_hash_netport.c

@@ -158,7 +158,8 @@ hash_netport4_uadt(struct ip_set *set, struct nlattr *tb[],
 	ipset_adtfn adtfn = set->variant->adt[adt];
 	struct hash_netport4_elem e = { .cidr = HOST_MASK - 1 };
 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
-	u32 port, port_to, p = 0, ip = 0, ip_to = 0;
+	u32 port, port_to, p = 0, ip = 0, ip_to = 0, ipn;
+	u64 n = 0;
 	bool with_ports = false;
 	u8 cidr;
 	int ret;
@@ -235,6 +236,14 @@ hash_netport4_uadt(struct ip_set *set, struct nlattr *tb[],
 	} else {
 		ip_set_mask_from_to(ip, ip_to, e.cidr + 1);
 	}
+	ipn = ip;
+	do {
+		ipn = ip_set_range_to_cidr(ipn, ip_to, &cidr);
+		n++;
+	} while (ipn++ < ip_to);
+
+	if (n*(port_to - port + 1) > IPSET_MAX_RANGE)
+		return -ERANGE;
 
 	if (retried) {
 		ip = ntohl(h->next.ip);

net/netfilter/ipset/ip_set_hash_netportnet.c

@@ -182,7 +182,8 @@ hash_netportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
 	struct hash_netportnet4_elem e = { };
 	struct ip_set_ext ext = IP_SET_INIT_UEXT(set);
 	u32 ip = 0, ip_to = 0, p = 0, port, port_to;
-	u32 ip2_from = 0, ip2_to = 0, ip2;
+	u32 ip2_from = 0, ip2_to = 0, ip2, ipn;
+	u64 n = 0, m = 0;
 	bool with_ports = false;
 	int ret;
 
@@ -284,6 +285,19 @@ hash_netportnet4_uadt(struct ip_set *set, struct nlattr *tb[],
 	} else {
 		ip_set_mask_from_to(ip2_from, ip2_to, e.cidr[1]);
 	}
+	ipn = ip;
+	do {
+		ipn = ip_set_range_to_cidr(ipn, ip_to, &e.cidr[0]);
+		n++;
+	} while (ipn++ < ip_to);
+	ipn = ip2_from;
+	do {
+		ipn = ip_set_range_to_cidr(ipn, ip2_to, &e.cidr[1]);
+		m++;
+	} while (ipn++ < ip2_to);
+
+	if (n*m*(port_to - port + 1) > IPSET_MAX_RANGE)
+		return -ERANGE;
 
 	if (retried) {
 		ip = ntohl(h->next.ip[0]);