Re: Regression in 4.16-rc7 - ipsec vpn broken

[Steffen Klassert <steffen.klassert@secunet.com>]

Please always make sure to Cc netdev@vger.kernel.org
on networking problems.

On Wed, Mar 28, 2018 at 10:21:32PM +0000, Derek Robson wrote:
> The ipsec VPN is broken in 4.16-rc7 and seem to have been broken in all of
> 4.15
> 
> connecting from an iphone seems to give a timeout.
> 
> 
> A bisect brings me to this commit as the one that is the issue.
> 
> commit: acf568ee859f098279eadf551612f103afdacb4e  (xfrm: Reinject
> transport-mode packets through tasklet)

I have a fix queued for this commit in the ipsec tree.

Can you please try if the patch below fixes your problems?

Thanks!

Subject: [PATCH] xfrm: Fix transport mode skb control buffer usage.

A recent commit introduced a new struct xfrm_trans_cb
that is used with the sk_buff control buffer. Unfortunately
it placed the structure in front of the control buffer and
overlooked that the IPv4/IPv6 control buffer is still needed
for some layer 4 protocols. As a result the IPv4/IPv6 control
buffer is overwritten with this structure. Fix this by setting
a apropriate header in front of the structure.

Fixes acf568ee859f ("xfrm: Reinject transport-mode packets ...")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/xfrm/xfrm_input.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 1472c0857975..81788105c164 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -26,6 +26,12 @@ struct xfrm_trans_tasklet {
 };
 
 struct xfrm_trans_cb {
+	union {
+		struct inet_skb_parm	h4;
+#if IS_ENABLED(CONFIG_IPV6)
+		struct inet6_skb_parm	h6;
+#endif
+	} header;
 	int (*finish)(struct net *net, struct sock *sk, struct sk_buff *skb);
 };
 
-- 
2.14.1