Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

Steffen Klassert says:

====================
pull request (net): ipsec 2015-10-22

1) Fix IPsec pre-encap fragmentation for GSO packets.
   From Herbert Xu.

2) Fix some header checks in _decode_session6.
   We skip the header informations if the data pointer points
   already behind the header in question for some protocols.
   This is because we call pskb_may_pull with a negative value
   converted to unsigened int from pskb_may_pull in this case.
   Skipping the header informations can lead to incorrect policy
   lookups. From Mathias Krause.

3) Allow to change the replay threshold and expiry timer of a
   state without having to set other attributes like replay
   counter and byte lifetime. Changing these other attributes
   may break the SA. From Michael Rossberg.

4) Fix pmtu discovery for local generated packets.
   We may fail dispatch to the inner address family.
   As a reault, the local error handler is not called
   and the mtu value is not reported back to userspace.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 8 deletions

diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index 09c76a7b474d..e15feb7b413d 100644
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -79,6 +79,7 @@ static int xfrm6_tunnel_check_size(struct sk_buff *skb)
 
 	if (!skb->ignore_df && skb->len > mtu) {
 		skb->dev = dst->dev;
+		skb->protocol = htons(ETH_P_IPV6);
 
 		if (xfrm6_local_dontfrag(skb))
 			xfrm6_local_rxpmtu(skb, mtu);
@@ -136,6 +137,7 @@ static int __xfrm6_output(struct sock *sk, struct sk_buff *skb)
 	struct dst_entry *dst = skb_dst(skb);
 	struct xfrm_state *x = dst->xfrm;
 	int mtu;
+	bool toobig;
 
 #ifdef CONFIG_NETFILTER
 	if (!x) {
@@ -144,25 +146,29 @@ static int __xfrm6_output(struct sock *sk, struct sk_buff *skb)
 	}
 #endif
 
+	if (x->props.mode != XFRM_MODE_TUNNEL)
+		goto skip_frag;
+
 	if (skb->protocol == htons(ETH_P_IPV6))
 		mtu = ip6_skb_dst_mtu(skb);
 	else
 		mtu = dst_mtu(skb_dst(skb));
 
-	if (skb->len > mtu && xfrm6_local_dontfrag(skb)) {
+	toobig = skb->len > mtu && !skb_is_gso(skb);
+
+	if (toobig && xfrm6_local_dontfrag(skb)) {
 		xfrm6_local_rxpmtu(skb, mtu);
 		return -EMSGSIZE;
-	} else if (!skb->ignore_df && skb->len > mtu && skb->sk) {
+	} else if (!skb->ignore_df && toobig && skb->sk) {
 		xfrm_local_error(skb, mtu);
 		return -EMSGSIZE;
 	}
 
-	if (x->props.mode == XFRM_MODE_TUNNEL &&
-	    ((skb->len > mtu && !skb_is_gso(skb)) ||
-		dst_allfrag(skb_dst(skb)))) {
+	if (toobig || dst_allfrag(skb_dst(skb)))
 		return ip6_fragment(sk, skb,
 				    x->outer_mode->afinfo->output_finish);
-	}
+
+skip_frag:
 	return x->outer_mode->afinfo->output_finish(sk, skb);
 }
 
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 5cedfda4b241..da55e0c85bb8 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -179,7 +179,8 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
 			return;
 
 		case IPPROTO_ICMPV6:
-			if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
+			if (!onlyproto && (nh + offset + 2 < skb->data ||
+			    pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
 				u8 *icmp;
 
 				nh = skb_network_header(skb);
@@ -193,7 +194,8 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
 #if IS_ENABLED(CONFIG_IPV6_MIP6)
 		case IPPROTO_MH:
 			offset += ipv6_optlen(exthdr);
-			if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
+			if (!onlyproto && (nh + offset + 3 < skb->data ||
+			    pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
 				struct ip6_mh *mh;
 
 				nh = skb_network_header(skb);