Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/gi…

…t/klassert/ipsec

Conflicts:
	net/ipv4/ip_vti.c

Steffen Klassert says:

====================
pull request (net): ipsec 2014-05-15

This pull request has a merge conflict in net/ipv4/ip_vti.c
between commit 8d89dcd ("vti: don't allow to add the same
tunnel twice") and commit a324523  ("vti4:Don't count header
length twice"). It can be solved like it is done in linux-next.

1) Fix a ipv6 xfrm output crash when a packet is rerouted
   by netfilter to not use IPsec.

2) vti4 counts some header lengths twice leading to an incorrect
   device mtu. Fix this by counting these headers only once.

3) We don't catch the case if an unsupported protocol is submitted
   to the xfrm protocol handlers, this can lead to NULL pointer
   dereferences. Fix this by adding the appropriate checks.

4) vti6 may unregister pernet ops twice on init errors.
   Fix this by removing one of the calls to do it only once.
   From Mathias Krause.

5) Set the vti tunnel mark before doing a lookup in the error
   handlers. Otherwise we don't find the correct xfrm state.
====================

The conflict in ip_vti.c was simple, 'net' had a commit
removing a line from vti_tunnel_init() and this tree
being merged had a commit adding a line to the same
location.

Signed-off-by: David S. Miller <[email protected]>

net/ipv4/ip_vti.c

@@ -239,6 +239,7 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 static int vti4_err(struct sk_buff *skb, u32 info)
 {
 	__be32 spi;
+	__u32 mark;
 	struct xfrm_state *x;
 	struct ip_tunnel *tunnel;
 	struct ip_esp_hdr *esph;
@@ -254,6 +255,8 @@ static int vti4_err(struct sk_buff *skb, u32 info)
 	if (!tunnel)
 		return -1;
 
+	mark = be32_to_cpu(tunnel->parms.o_key);
+
 	switch (protocol) {
 	case IPPROTO_ESP:
 		esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
@@ -281,7 +284,7 @@ static int vti4_err(struct sk_buff *skb, u32 info)
 		return 0;
 	}
 
-	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
+	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
 			      spi, protocol, AF_INET);
 	if (!x)
 		return 0;

net/ipv4/xfrm4_output.c

@@ -62,38 +62,42 @@ int xfrm4_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
 	if (err)
 		return err;
 
-	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
-	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED;
-
-	skb->protocol = htons(ETH_P_IP);
+	IPCB(skb)->flags |= IPSKB_XFRM_TUNNEL_SIZE;
 
 	return x->outer_mode->output2(x, skb);
 }
 EXPORT_SYMBOL(xfrm4_prepare_output);
 
 int xfrm4_output_finish(struct sk_buff *skb)
 {
+	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+	skb->protocol = htons(ETH_P_IP);
+
+#ifdef CONFIG_NETFILTER
+	IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
+#endif
+
+	return xfrm_output(skb);
+}
+
+static int __xfrm4_output(struct sk_buff *skb)
+{
+	struct xfrm_state *x = skb_dst(skb)->xfrm;
+
 #ifdef CONFIG_NETFILTER
-	if (!skb_dst(skb)->xfrm) {
+	if (!x) {
 		IPCB(skb)->flags |= IPSKB_REROUTED;
 		return dst_output(skb);
 	}
-
-	IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
 #endif
 
-	skb->protocol = htons(ETH_P_IP);
-	return xfrm_output(skb);
+	return x->outer_mode->afinfo->output_finish(skb);
 }
 
 int xfrm4_output(struct sock *sk, struct sk_buff *skb)
 {
-	struct dst_entry *dst = skb_dst(skb);
-	struct xfrm_state *x = dst->xfrm;
-
 	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb,
-			    NULL, dst->dev,
-			    x->outer_mode->afinfo->output_finish,
+			    NULL, skb_dst(skb)->dev, __xfrm4_output,
 			    !(IPCB(skb)->flags & IPSKB_REROUTED));
 }
 

net/ipv4/xfrm4_protocol.c

@@ -50,8 +50,12 @@ int xfrm4_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
 {
 	int ret;
 	struct xfrm4_protocol *handler;
+	struct xfrm4_protocol __rcu **head = proto_handlers(protocol);
 
-	for_each_protocol_rcu(*proto_handlers(protocol), handler)
+	if (!head)
+		return 0;
+
+	for_each_protocol_rcu(*head, handler)
 		if ((ret = handler->cb_handler(skb, err)) <= 0)
 			return ret;
 
@@ -64,15 +68,20 @@ int xfrm4_rcv_encap(struct sk_buff *skb, int nexthdr, __be32 spi,
 {
 	int ret;
 	struct xfrm4_protocol *handler;
+	struct xfrm4_protocol __rcu **head = proto_handlers(nexthdr);
 
 	XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL;
 	XFRM_SPI_SKB_CB(skb)->family = AF_INET;
 	XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
 
-	for_each_protocol_rcu(*proto_handlers(nexthdr), handler)
+	if (!head)
+		goto out;
+
+	for_each_protocol_rcu(*head, handler)
 		if ((ret = handler->input_handler(skb, nexthdr, spi, encap_type)) != -EINVAL)
 			return ret;
 
+out:
 	icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
 
 	kfree_skb(skb);
@@ -208,6 +217,9 @@ int xfrm4_protocol_register(struct xfrm4_protocol *handler,
 	int ret = -EEXIST;
 	int priority = handler->priority;
 
+	if (!proto_handlers(protocol) || !netproto(protocol))
+		return -EINVAL;
+
 	mutex_lock(&xfrm4_protocol_mutex);
 
 	if (!rcu_dereference_protected(*proto_handlers(protocol),
@@ -250,6 +262,9 @@ int xfrm4_protocol_deregister(struct xfrm4_protocol *handler,
 	struct xfrm4_protocol *t;
 	int ret = -ENOENT;
 
+	if (!proto_handlers(protocol) || !netproto(protocol))
+		return -EINVAL;
+
 	mutex_lock(&xfrm4_protocol_mutex);
 
 	for (pprev = proto_handlers(protocol);

net/ipv6/ip6_vti.c

@@ -511,6 +511,7 @@ static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 		    u8 type, u8 code, int offset, __be32 info)
 {
 	__be32 spi;
+	__u32 mark;
 	struct xfrm_state *x;
 	struct ip6_tnl *t;
 	struct ip_esp_hdr *esph;
@@ -524,6 +525,8 @@ static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	if (!t)
 		return -1;
 
+	mark = be32_to_cpu(t->parms.o_key);
+
 	switch (protocol) {
 	case IPPROTO_ESP:
 		esph = (struct ip_esp_hdr *)(skb->data + offset);
@@ -545,7 +548,7 @@ static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 	    type != NDISC_REDIRECT)
 		return 0;
 
-	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
+	x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
 			      spi, protocol, AF_INET6);
 	if (!x)
 		return 0;
@@ -1097,7 +1100,6 @@ static int __init vti6_tunnel_init(void)
 
 	err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP);
 	if (err < 0) {
-		unregister_pernet_device(&vti6_net_ops);
 		pr_err("%s: can't register vti6 protocol\n", __func__);
 
 		goto out;
@@ -1106,7 +1108,6 @@ static int __init vti6_tunnel_init(void)
 	err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH);
 	if (err < 0) {
 		xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
-		unregister_pernet_device(&vti6_net_ops);
 		pr_err("%s: can't register vti6 protocol\n", __func__);
 
 		goto out;
@@ -1116,7 +1117,6 @@ static int __init vti6_tunnel_init(void)
 	if (err < 0) {
 		xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH);
 		xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP);
-		unregister_pernet_device(&vti6_net_ops);
 		pr_err("%s: can't register vti6 protocol\n", __func__);
 
 		goto out;

net/ipv6/xfrm6_output.c

@@ -114,12 +114,6 @@ int xfrm6_prepare_output(struct xfrm_state *x, struct sk_buff *skb)
 	if (err)
 		return err;
 
-	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
-#ifdef CONFIG_NETFILTER
-	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
-#endif
-
-	skb->protocol = htons(ETH_P_IPV6);
 	skb->local_df = 1;
 
 	return x->outer_mode->output2(x, skb);
@@ -128,11 +122,13 @@ EXPORT_SYMBOL(xfrm6_prepare_output);
 
 int xfrm6_output_finish(struct sk_buff *skb)
 {
+	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+	skb->protocol = htons(ETH_P_IPV6);
+
 #ifdef CONFIG_NETFILTER
 	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
 #endif
 
-	skb->protocol = htons(ETH_P_IPV6);
 	return xfrm_output(skb);
 }
 
@@ -142,6 +138,13 @@ static int __xfrm6_output(struct sk_buff *skb)
 	struct xfrm_state *x = dst->xfrm;
 	int mtu;
 
+#ifdef CONFIG_NETFILTER
+	if (!x) {
+		IP6CB(skb)->flags |= IP6SKB_REROUTED;
+		return dst_output(skb);
+	}
+#endif
+
 	if (skb->protocol == htons(ETH_P_IPV6))
 		mtu = ip6_skb_dst_mtu(skb);
 	else
@@ -165,6 +168,7 @@ static int __xfrm6_output(struct sk_buff *skb)
 
 int xfrm6_output(struct sock *sk, struct sk_buff *skb)
 {
-	return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL,
-		       skb_dst(skb)->dev, __xfrm6_output);
+	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb,
+			    NULL, skb_dst(skb)->dev, __xfrm6_output,
+			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
 }

net/ipv6/xfrm6_protocol.c

@@ -50,6 +50,10 @@ int xfrm6_rcv_cb(struct sk_buff *skb, u8 protocol, int err)
 {
 	int ret;
 	struct xfrm6_protocol *handler;
+	struct xfrm6_protocol __rcu **head = proto_handlers(protocol);
+
+	if (!head)
+		return 0;
 
 	for_each_protocol_rcu(*proto_handlers(protocol), handler)
 		if ((ret = handler->cb_handler(skb, err)) <= 0)
@@ -184,10 +188,12 @@ int xfrm6_protocol_register(struct xfrm6_protocol *handler,
 	struct xfrm6_protocol __rcu **pprev;
 	struct xfrm6_protocol *t;
 	bool add_netproto = false;
-
 	int ret = -EEXIST;
 	int priority = handler->priority;
 
+	if (!proto_handlers(protocol) || !netproto(protocol))
+		return -EINVAL;
+
 	mutex_lock(&xfrm6_protocol_mutex);
 
 	if (!rcu_dereference_protected(*proto_handlers(protocol),
@@ -230,6 +236,9 @@ int xfrm6_protocol_deregister(struct xfrm6_protocol *handler,
 	struct xfrm6_protocol *t;
 	int ret = -ENOENT;
 
+	if (!proto_handlers(protocol) || !netproto(protocol))
+		return -EINVAL;
+
 	mutex_lock(&xfrm6_protocol_mutex);
 
 	for (pprev = proto_handlers(protocol);