ovpn: validate peer VPN addresses

index c95656ca7c35..68a2b05689ef 100644
@@ -990,10 +990,11 @@ void ovpn_peer_hash_vpn_ip(struct ovpn_peer *peer)
 	if (hlist_unhashed(&peer->hash_entry_id))
 		return;
 
-	if (peer->vpn_addrs.ipv4.s_addr != htonl(INADDR_ANY)) {
-		/* remove potential old hashing */
-		hlist_nulls_del_init_rcu(&peer->hash_entry_addr4);
+	/* remove potential old hashing */
+	hlist_nulls_del_init_rcu(&peer->hash_entry_addr4);
+	hlist_nulls_del_init_rcu(&peer->hash_entry_addr6);
 
+	if (peer->vpn_addrs.ipv4.s_addr != htonl(INADDR_ANY)) {
 		nhead = ovpn_get_hash_head(peer->ovpn->peers->by_vpn_addr4,
 					   &peer->vpn_addrs.ipv4,
 					   sizeof(peer->vpn_addrs.ipv4));

@@ -1001,9 +1002,6 @@ void ovpn_peer_hash_vpn_ip(struct ovpn_peer *peer)
 	}
 
 	if (!ipv6_addr_any(&peer->vpn_addrs.ipv6)) {
-		/* remove potential old hashing */
-		hlist_nulls_del_init_rcu(&peer->hash_entry_addr6);
-
 		nhead = ovpn_get_hash_head(peer->ovpn->peers->by_vpn_addr6,
 					   &peer->vpn_addrs.ipv6,
 					   sizeof(peer->vpn_addrs.ipv6));

index 4dad85294198..a444930234b6 100644
@@ -474,8 +474,10 @@ int ovpn_nl_peer_new_doit(struct sk_buff *skb, struct genl_info *info)
 
 int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
 	struct ovpn_priv *ovpn = info->user_ptr[0];
+	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
+	struct in6_addr vpn_addr6;
+	struct in_addr vpn_addr4;
 	struct ovpn_socket *sock;
 	struct ovpn_peer *peer;
 	u32 peer_id;

@@ -522,28 +524,47 @@ int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info)
 	rcu_read_unlock();
 
 	spin_lock_bh(&ovpn->lock);
-	ret = ovpn_nl_peer_modify(peer, info, attrs);
-	if (ret < 0) {
-		spin_unlock_bh(&ovpn->lock);
-		ovpn_peer_put(peer);
-		return ret;
+
+	/* reject peer with conflicting VPN address */
+	if (attrs[OVPN_A_PEER_VPN_IPV4]) {
+		vpn_addr4.s_addr = nla_get_in_addr(attrs[OVPN_A_PEER_VPN_IPV4]);
+		if (ovpn_peer_vpn_addr_conflict4(ovpn, peer, &vpn_addr4))
+			goto addr_conflict;
 	}
+	if (attrs[OVPN_A_PEER_VPN_IPV6]) {
+		vpn_addr6 = nla_get_in6_addr(attrs[OVPN_A_PEER_VPN_IPV6]);
+		if (ovpn_peer_vpn_addr_conflict6(ovpn, peer, &vpn_addr6))
+			goto addr_conflict;
+	}
+
+	ret = ovpn_nl_peer_modify(peer, info, attrs);
+	if (ret < 0)
+		goto unlock;
 
 	/* ret == 1 means that VPN IPv4/6 has been modified and rehashing
 	 * is required
 	 */
-	if (ret > 0)
+	if (ret > 0) {
 		ovpn_peer_hash_vpn_ip(peer);
+		ret = 0;
+	}
 	/* if the remote endpoint was updated, the by_transp_addr hash bucket
 	 * also needs to be refreshed, otherwise incoming packets from the new
 	 * remote address would fail the lockless lookup
 	 */
 	if (attrs[OVPN_A_PEER_REMOTE_IPV4] || attrs[OVPN_A_PEER_REMOTE_IPV6])
 		ovpn_peer_hash_transp_addr(peer);
+
+unlock:
 	spin_unlock_bh(&ovpn->lock);
 	ovpn_peer_put(peer);
 
-	return 0;
+	return ret;
+addr_conflict:
+	NL_SET_ERR_MSG_FMT_MOD(info->extack,
+			       "VPN IP is already assigned to another peer");
+	ret = -EADDRINUSE;
+	goto unlock;
 }
 
 static int ovpn_nl_send_peer(struct sk_buff *skb, const struct genl_info *info,

85 lines not on this page · raw message

index dfa5c0037e02..a1cbd4013349 100644
@@ -149,6 +149,12 @@ struct ovpn_peer *ovpn_peer_get_by_transp_addr(struct ovpn_priv *ovpn,
 struct ovpn_peer *ovpn_peer_get_by_id(struct ovpn_priv *ovpn, u32 peer_id);
 struct ovpn_peer *ovpn_peer_get_by_dst(struct ovpn_priv *ovpn,
 				       struct sk_buff *skb);
+bool ovpn_peer_vpn_addr_conflict4(struct ovpn_priv *ovpn,
+				  const struct ovpn_peer *peer,
+				  const struct in_addr *addr);
+bool ovpn_peer_vpn_addr_conflict6(struct ovpn_priv *ovpn,
+				  const struct ovpn_peer *peer,
+				  const struct in6_addr *addr);
 void ovpn_peer_hash_vpn_ip(struct ovpn_peer *peer);
 void ovpn_peer_hash_transp_addr(struct ovpn_peer *peer);
 bool ovpn_peer_check_by_src(struct ovpn_priv *ovpn, struct sk_buff *skb,

index a444930234b6..a0ed09278a6b 100644
@@ -346,8 +346,10 @@ static int ovpn_nl_peer_modify(struct ovpn_peer *peer, struct genl_info *info,
 
 int ovpn_nl_peer_new_doit(struct sk_buff *skb, struct genl_info *info)
 {
-	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
+	struct in_addr vpn_addr4 = { .s_addr = htonl(INADDR_ANY) };
+	struct in6_addr vpn_addr6 = IN6ADDR_ANY_INIT;
 	struct ovpn_priv *ovpn = info->user_ptr[0];
+	struct nlattr *attrs[OVPN_A_PEER_MAX + 1];
 	struct ovpn_socket *ovpn_sock;
 	struct socket *sock = NULL;
 	struct ovpn_peer *peer;

@@ -371,11 +373,20 @@ int ovpn_nl_peer_new_doit(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 
 	/* in MP mode VPN IPs are required for selecting the right peer */
-	if (ovpn->mode == OVPN_MODE_MP && !attrs[OVPN_A_PEER_VPN_IPV4] &&
-	    !attrs[OVPN_A_PEER_VPN_IPV6]) {
-		NL_SET_ERR_MSG_FMT_MOD(info->extack,
-				       "VPN IP must be provided in MP mode");
-		return -EINVAL;
+	if (ovpn->mode == OVPN_MODE_MP) {
+		if (attrs[OVPN_A_PEER_VPN_IPV4])
+			vpn_addr4.s_addr =
+				nla_get_in_addr(attrs[OVPN_A_PEER_VPN_IPV4]);
+		if (attrs[OVPN_A_PEER_VPN_IPV6])
+			vpn_addr6 =
+				nla_get_in6_addr(attrs[OVPN_A_PEER_VPN_IPV6]);
+
+		if (vpn_addr4.s_addr == htonl(INADDR_ANY) &&
+		    ipv6_addr_any(&vpn_addr6)) {
+			NL_SET_ERR_MSG_FMT_MOD(info->extack,
+					       "at least one VPN IP must be configured in MP mode");
+			return -EINVAL;
+		}
 	}
 
 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);

@@ -525,6 +536,9 @@ int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info)
 
 	spin_lock_bh(&ovpn->lock);
 
+	vpn_addr4 = peer->vpn_addrs.ipv4;
+	vpn_addr6 = peer->vpn_addrs.ipv6;
+
 	/* reject peer with conflicting VPN address */
 	if (attrs[OVPN_A_PEER_VPN_IPV4]) {
 		vpn_addr4.s_addr = nla_get_in_addr(attrs[OVPN_A_PEER_VPN_IPV4]);

@@ -537,6 +551,16 @@ int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info)
 			goto addr_conflict;
 	}
 
+	/* in MP mode VPN IPs are required for selecting the right peer */
+	if (ovpn->mode == OVPN_MODE_MP &&
+	    vpn_addr4.s_addr == htonl(INADDR_ANY) &&
+	    ipv6_addr_any(&vpn_addr6)) {
+		NL_SET_ERR_MSG_FMT_MOD(info->extack,
+				       "at least one VPN IP must be configured in MP mode");
+		ret = -EINVAL;
+		goto unlock;
+	}
+
 	ret = ovpn_nl_peer_modify(peer, info, attrs);
 	if (ret < 0)
 		goto unlock;

index a0ed09278a6b..e9fef784dfc1 100644
@@ -179,6 +179,39 @@ static sa_family_t ovpn_nl_family_get(struct nlattr *addr4,
 	return AF_UNSPEC;
 }
 
+static int ovpn_nl_peer_check_vpn_addrs(const struct in_addr *addr4,
+					const struct in6_addr *addr6,
+					struct genl_info *info)
+{
+	int addr6_type;
+
+	if (addr4->s_addr == htonl(INADDR_ANY) && ipv6_addr_any(addr6)) {
+		NL_SET_ERR_MSG_MOD(info->extack,
+				   "at least one VPN IP must be configured in MP mode");
+		return -EINVAL;
+	}
+
+	if (ipv4_is_multicast(addr4->s_addr) || ipv4_is_lbcast(addr4->s_addr) ||
+	    ipv4_is_loopback(addr4->s_addr)) {
+		NL_SET_ERR_MSG_MOD(info->extack,
+				   "VPN IPv4 address must be valid unicast or any");
+		return -EADDRNOTAVAIL;
+	}
+
+	if (!ipv6_addr_any(addr6)) {
+		addr6_type = ipv6_addr_type(addr6);
+
+		if (!(addr6_type & IPV6_ADDR_UNICAST) ||
+		    (addr6_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_COMPATv4))) {
+			NL_SET_ERR_MSG_MOD(info->extack,
+					   "VPN IPv6 address must be valid unicast or any");
+			return -EADDRNOTAVAIL;
+		}
+	}
+
+	return 0;
+}
+
 static int ovpn_nl_peer_precheck(struct ovpn_priv *ovpn,
 				 struct genl_info *info,
 				 struct nlattr **attrs)

@@ -381,12 +414,10 @@ int ovpn_nl_peer_new_doit(struct sk_buff *skb, struct genl_info *info)
 			vpn_addr6 =
 				nla_get_in6_addr(attrs[OVPN_A_PEER_VPN_IPV6]);
 
-		if (vpn_addr4.s_addr == htonl(INADDR_ANY) &&
-		    ipv6_addr_any(&vpn_addr6)) {
-			NL_SET_ERR_MSG_FMT_MOD(info->extack,
-					       "at least one VPN IP must be configured in MP mode");
-			return -EINVAL;
-		}
+		ret = ovpn_nl_peer_check_vpn_addrs(&vpn_addr4, &vpn_addr6,
+						   info);
+		if (ret < 0)
+			return ret;
 	}
 
 	peer_id = nla_get_u32(attrs[OVPN_A_PEER_ID]);

@@ -552,13 +583,11 @@ int ovpn_nl_peer_set_doit(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	/* in MP mode VPN IPs are required for selecting the right peer */
-	if (ovpn->mode == OVPN_MODE_MP &&
-	    vpn_addr4.s_addr == htonl(INADDR_ANY) &&
-	    ipv6_addr_any(&vpn_addr6)) {
-		NL_SET_ERR_MSG_FMT_MOD(info->extack,
-				       "at least one VPN IP must be configured in MP mode");
-		ret = -EINVAL;
-		goto unlock;
+	if (ovpn->mode == OVPN_MODE_MP) {
+		ret = ovpn_nl_peer_check_vpn_addrs(&vpn_addr4, &vpn_addr6,
+						   info);
+		if (ret < 0)
+			goto unlock;
 	}
 
 	ret = ovpn_nl_peer_modify(peer, info, attrs);

96 lines not on this page · raw message