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>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 3110c3fbee20..f094d4b3520d 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/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)) {