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

Steffen Klassert says:

====================
pull request (net): ipsec 2018-10-01

1) Validate address prefix lengths in the xfrm selector,
   otherwise we may hit undefined behaviour in the
   address matching functions if the prefix is too
   big for the given address family.

2) Fix skb leak on local message size errors.
   From Thadeu Lima de Souza Cascardo.

3) We currently reset the transport header back to the network
   header after a transport mode transformation is applied. This
   leads to an incorrect transport header when multiple transport
   mode transformations are applied. Reset the transport header
   only after all transformations are already applied to fix this.
   From Sowmini Varadhan.

4) We only support one offloaded xfrm, so reset crypto_done after
   the first transformation in xfrm_input(). Otherwise we may call
   the wrong input method for subsequent transformations.
   From Sowmini Varadhan.

5) Fix NULL pointer dereference when skb_dst_force clears the dst_entry.
   skb_dst_force does not really force a dst refcount anymore, it might
   clear it instead. xfrm code did not expect this, add a check to not
   dereference skb_dst() if it was cleared by skb_dst_force.

6) Validate xfrm template mode, otherwise we can get a stack-out-of-bounds
   read in xfrm_state_find. From Sean Tranchetti.

Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/xfrm4_input.c

@@ -67,6 +67,7 @@ int xfrm4_transport_finish(struct sk_buff *skb, int async)
 
 	if (xo && (xo->flags & XFRM_GRO)) {
 		skb_mac_header_rebuild(skb);
+		skb_reset_transport_header(skb);
 		return 0;
 	}
 

net/ipv4/xfrm4_mode_transport.c

@@ -46,7 +46,6 @@ static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 {
 	int ihl = skb->data - skb_transport_header(skb);
-	struct xfrm_offload *xo = xfrm_offload(skb);
 
 	if (skb->transport_header != skb->network_header) {
 		memmove(skb_transport_header(skb),
@@ -54,7 +53,6 @@ static int xfrm4_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 		skb->network_header = skb->transport_header;
 	}
 	ip_hdr(skb)->tot_len = htons(skb->len + ihl);
-	if (!xo || !(xo->flags & XFRM_GRO))
 	skb_reset_transport_header(skb);
 	return 0;
 }

net/ipv6/xfrm6_input.c

@@ -59,6 +59,7 @@ int xfrm6_transport_finish(struct sk_buff *skb, int async)
 
 	if (xo && (xo->flags & XFRM_GRO)) {
 		skb_mac_header_rebuild(skb);
+		skb_reset_transport_header(skb);
 		return -1;
 	}
 

net/ipv6/xfrm6_mode_transport.c

@@ -51,7 +51,6 @@ static int xfrm6_transport_output(struct xfrm_state *x, struct sk_buff *skb)
 static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 {
 	int ihl = skb->data - skb_transport_header(skb);
-	struct xfrm_offload *xo = xfrm_offload(skb);
 
 	if (skb->transport_header != skb->network_header) {
 		memmove(skb_transport_header(skb),
@@ -60,7 +59,6 @@ static int xfrm6_transport_input(struct xfrm_state *x, struct sk_buff *skb)
 	}
 	ipv6_hdr(skb)->payload_len = htons(skb->len + ihl -
 					   sizeof(struct ipv6hdr));
-	if (!xo || !(xo->flags & XFRM_GRO))
 	skb_reset_transport_header(skb);
 	return 0;
 }

net/ipv6/xfrm6_output.c

@@ -170,9 +170,11 @@ static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 
 	if (toobig && xfrm6_local_dontfrag(skb)) {
 		xfrm6_local_rxpmtu(skb, mtu);
+		kfree_skb(skb);
 		return -EMSGSIZE;
 	} else if (!skb->ignore_df && toobig && skb->sk) {
 		xfrm_local_error(skb, mtu);
+		kfree_skb(skb);
 		return -EMSGSIZE;
 	}
 

net/xfrm/xfrm_input.c

@@ -458,6 +458,7 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMINHDRERROR);
 			goto drop;
 		}
+		crypto_done = false;
 	} while (!err);
 
 	err = xfrm_rcv_cb(skb, family, x->type->proto, 0);

net/xfrm/xfrm_output.c

@@ -100,6 +100,10 @@ static int xfrm_output_one(struct sk_buff *skb, int err)
 		spin_unlock_bh(&x->lock);
 
 		skb_dst_force(skb);
+		if (!skb_dst(skb)) {
+			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
+			goto error_nolock;
+		}
 
 		if (xfrm_offload(skb)) {
 			x->type_offload->encap(x, skb);

net/xfrm/xfrm_policy.c

@@ -2491,6 +2491,10 @@ int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
 	}
 
 	skb_dst_force(skb);
+	if (!skb_dst(skb)) {
+		XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
+		return 0;
+	}
 
 	dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
 	if (IS_ERR(dst)) {

net/xfrm/xfrm_user.c

@@ -151,10 +151,16 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 	err = -EINVAL;
 	switch (p->family) {
 	case AF_INET:
+		if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32)
+			goto out;
+
 		break;
 
 	case AF_INET6:
 #if IS_ENABLED(CONFIG_IPV6)
+		if (p->sel.prefixlen_d > 128 || p->sel.prefixlen_s > 128)
+			goto out;
+
 		break;
 #else
 		err = -EAFNOSUPPORT;
@@ -1396,10 +1402,16 @@ static int verify_newpolicy_info(struct xfrm_userpolicy_info *p)
 
 	switch (p->sel.family) {
 	case AF_INET:
+		if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32)
+			return -EINVAL;
+
 		break;
 
 	case AF_INET6:
 #if IS_ENABLED(CONFIG_IPV6)
+		if (p->sel.prefixlen_d > 128 || p->sel.prefixlen_s > 128)
+			return -EINVAL;
+
 		break;
 #else
 		return  -EAFNOSUPPORT;
@@ -1480,6 +1492,9 @@ static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family)
 		    (ut[i].family != prev_family))
 			return -EINVAL;
 
+		if (ut[i].mode >= XFRM_MODE_MAX)
+			return -EINVAL;
+
 		prev_family = ut[i].family;
 
 		switch (ut[i].family) {