ipvs: fix oops in backup for fwmark conn templates

Fixes bug http://bugzilla.kernel.org/show_bug.cgi?id=10556
where conn templates with protocol=IPPROTO_IP can oops backup box.

        Result from ip_vs_proto_get() should be checked because
protocol value can be invalid or unsupported in backup. But
for valid message we should not fail for templates which use
IPPROTO_IP. Also, add checks to validate message limits and
connection state. Show state NONE for templates using IPPROTO_IP.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip_vs.h

@@ -405,7 +405,8 @@ struct sk_buff;
 struct ip_vs_protocol {
 	struct ip_vs_protocol	*next;
 	char			*name;
-	__u16			protocol;
+	u16			protocol;
+	u16			num_states;
 	int			dont_defrag;
 	atomic_t		appcnt;		/* counter of proto app incs */
 	int			*timeout_table;	/* protocol timeout table */

net/ipv4/ipvs/ip_vs_proto.c

@@ -148,7 +148,7 @@ const char * ip_vs_state_name(__u16 proto, int state)
 	struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
 
 	if (pp == NULL || pp->state_name == NULL)
-		return "ERR!";
+		return (IPPROTO_IP == proto) ? "NONE" : "ERR!";
 	return pp->state_name(state);
 }
 

net/ipv4/ipvs/ip_vs_proto_ah.c

@@ -160,6 +160,7 @@ static void ah_exit(struct ip_vs_protocol *pp)
 struct ip_vs_protocol ip_vs_protocol_ah = {
 	.name =			"AH",
 	.protocol =		IPPROTO_AH,
+	.num_states =		1,
 	.dont_defrag =		1,
 	.init =			ah_init,
 	.exit =			ah_exit,

net/ipv4/ipvs/ip_vs_proto_esp.c

@@ -159,6 +159,7 @@ static void esp_exit(struct ip_vs_protocol *pp)
 struct ip_vs_protocol ip_vs_protocol_esp = {
 	.name =			"ESP",
 	.protocol =		IPPROTO_ESP,
+	.num_states =		1,
 	.dont_defrag =		1,
 	.init =			esp_init,
 	.exit =			esp_exit,

net/ipv4/ipvs/ip_vs_proto_tcp.c

@@ -594,6 +594,7 @@ static void ip_vs_tcp_exit(struct ip_vs_protocol *pp)
 struct ip_vs_protocol ip_vs_protocol_tcp = {
 	.name =			"TCP",
 	.protocol =		IPPROTO_TCP,
+	.num_states =		IP_VS_TCP_S_LAST,
 	.dont_defrag =		0,
 	.appcnt =		ATOMIC_INIT(0),
 	.init =			ip_vs_tcp_init,

net/ipv4/ipvs/ip_vs_proto_udp.c

@@ -409,6 +409,7 @@ static void udp_exit(struct ip_vs_protocol *pp)
 struct ip_vs_protocol ip_vs_protocol_udp = {
 	.name =			"UDP",
 	.protocol =		IPPROTO_UDP,
+	.num_states =		IP_VS_UDP_S_LAST,
 	.dont_defrag =		0,
 	.init =			udp_init,
 	.exit =			udp_exit,

net/ipv4/ipvs/ip_vs_sync.c

@@ -288,11 +288,16 @@ static void ip_vs_process_message(const char *buffer, const size_t buflen)
 	char *p;
 	int i;
 
+	if (buflen < sizeof(struct ip_vs_sync_mesg)) {
+		IP_VS_ERR_RL("sync message header too short\n");
+		return;
+	}
+
 	/* Convert size back to host byte order */
 	m->size = ntohs(m->size);
 
 	if (buflen != m->size) {
-		IP_VS_ERR("bogus message\n");
+		IP_VS_ERR_RL("bogus sync message size\n");
 		return;
 	}
 
@@ -307,9 +312,48 @@ static void ip_vs_process_message(const char *buffer, const size_t buflen)
 	for (i=0; i<m->nr_conns; i++) {
 		unsigned flags, state;
 
-		s = (struct ip_vs_sync_conn *)p;
+		if (p + SIMPLE_CONN_SIZE > buffer+buflen) {
+			IP_VS_ERR_RL("bogus conn in sync message\n");
+			return;
+		}
+		s = (struct ip_vs_sync_conn *) p;
 		flags = ntohs(s->flags) | IP_VS_CONN_F_SYNC;
+		flags &= ~IP_VS_CONN_F_HASHED;
+		if (flags & IP_VS_CONN_F_SEQ_MASK) {
+			opt = (struct ip_vs_sync_conn_options *)&s[1];
+			p += FULL_CONN_SIZE;
+			if (p > buffer+buflen) {
+				IP_VS_ERR_RL("bogus conn options in sync message\n");
+				return;
+			}
+		} else {
+			opt = NULL;
+			p += SIMPLE_CONN_SIZE;
+		}
+
 		state = ntohs(s->state);
+		if (!(flags & IP_VS_CONN_F_TEMPLATE)) {
+			pp = ip_vs_proto_get(s->protocol);
+			if (!pp) {
+				IP_VS_ERR_RL("Unsupported protocol %u in sync msg\n",
+					s->protocol);
+				continue;
+			}
+			if (state >= pp->num_states) {
+				IP_VS_DBG(2, "Invalid %s state %u in sync msg\n",
+					pp->name, state);
+				continue;
+			}
+		} else {
+			/* protocol in templates is not used for state/timeout */
+			pp = NULL;
+			if (state > 0) {
+				IP_VS_DBG(2, "Invalid template state %u in sync msg\n",
+					state);
+				state = 0;
+			}
+		}
+
 		if (!(flags & IP_VS_CONN_F_TEMPLATE))
 			cp = ip_vs_conn_in_get(s->protocol,
 					       s->caddr, s->cport,
@@ -345,14 +389,9 @@ static void ip_vs_process_message(const char *buffer, const size_t buflen)
 				IP_VS_ERR("ip_vs_conn_new failed\n");
 				return;
 			}
-			cp->state = state;
 		} else if (!cp->dest) {
 			dest = ip_vs_try_bind_dest(cp);
-			if (!dest) {
-				/* it is an unbound entry created by
-				 * synchronization */
-				cp->flags = flags | IP_VS_CONN_F_HASHED;
-			} else
+			if (dest)
 				atomic_dec(&dest->refcnt);
 		} else if ((cp->dest) && (cp->protocol == IPPROTO_TCP) &&
 			   (cp->state != state)) {
@@ -371,23 +410,22 @@ static void ip_vs_process_message(const char *buffer, const size_t buflen)
 			}
 		}
 
-		if (flags & IP_VS_CONN_F_SEQ_MASK) {
-			opt = (struct ip_vs_sync_conn_options *)&s[1];
+		if (opt)
 			memcpy(&cp->in_seq, opt, sizeof(*opt));
-			p += FULL_CONN_SIZE;
-		} else
-			p += SIMPLE_CONN_SIZE;
-
 		atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]);
 		cp->state = state;
-		pp = ip_vs_proto_get(s->protocol);
-		cp->timeout = pp->timeout_table[cp->state];
+		cp->old_state = cp->state;
+		/*
+		 * We can not recover the right timeout for templates
+		 * in all cases, we can not find the right fwmark
+		 * virtual service. If needed, we can do it for
+		 * non-fwmark persistent services.
+		 */
+		if (!(flags & IP_VS_CONN_F_TEMPLATE) && pp->timeout_table)
+			cp->timeout = pp->timeout_table[state];
+		else
+			cp->timeout = (3*60*HZ);
 		ip_vs_conn_put(cp);
-
-		if (p > buffer+buflen) {
-			IP_VS_ERR("bogus message\n");
-			return;
-		}
 	}
 }