diff mbox series

[net] xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto

Message ID 1520190232-7208-1-git-send-email-yossiku@mellanox.com
State Awaiting Upstream, archived
Delegated to: David Miller
Headers show
Series [net] xfrm: Verify MAC header exists before overwriting eth_hdr(skb)->h_proto | expand

Commit Message

Yossi Kuperman March 4, 2018, 7:03 p.m. UTC 
From: Yossi Kuperman <yossiku@mellanox.com>

Artem Savkov reported that commit 5efec5c655dd leads to a packet loss under
IPSec configuration. It appears that his setup consists of a TUN device,
which does not have a MAC header.

Make sure MAC header exists.

Note: TUN device sets a MAC header pointer, although it does not have one.

Fixes: 5efec5c655dd ("xfrm: Fix eth_hdr(skb)->h_proto to reflect inner IP version")
Reported-by: Artem Savkov <artem.savkov@gmail.com>
Tested-by: Artem Savkov <artem.savkov@gmail.com>
Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>
---
 net/ipv4/xfrm4_mode_tunnel.c | 3 ++-
 net/ipv6/xfrm6_mode_tunnel.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

Comments

Steffen Klassert March 7, 2018, 12:57 p.m. UTC | #1 
On Sun, Mar 04, 2018 at 09:03:52PM +0200, yossiku@mellanox.com wrote:
> From: Yossi Kuperman <yossiku@mellanox.com>
> 
> Artem Savkov reported that commit 5efec5c655dd leads to a packet loss under
> IPSec configuration. It appears that his setup consists of a TUN device,
> which does not have a MAC header.
> 
> Make sure MAC header exists.
> 
> Note: TUN device sets a MAC header pointer, although it does not have one.
> 
> Fixes: 5efec5c655dd ("xfrm: Fix eth_hdr(skb)->h_proto to reflect inner IP version")
> Reported-by: Artem Savkov <artem.savkov@gmail.com>
> Tested-by: Artem Savkov <artem.savkov@gmail.com>
> Signed-off-by: Yossi Kuperman <yossiku@mellanox.com>

Applied, thanks Yossi!
diff mbox series

Patch

diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index 63faeee..2a9764b 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -92,7 +92,8 @@  static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	skb_reset_network_header(skb);
 	skb_mac_header_rebuild(skb);
-	eth_hdr(skb)->h_proto = skb->protocol;
+	if (skb->mac_len)
+		eth_hdr(skb)->h_proto = skb->protocol;
 
 	err = 0;
 
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index bb935a3..de1b0b8 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -92,7 +92,8 @@  static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	skb_reset_network_header(skb);
 	skb_mac_header_rebuild(skb);
-	eth_hdr(skb)->h_proto = skb->protocol;
+	if (skb->mac_len)
+		eth_hdr(skb)->h_proto = skb->protocol;
 
 	err = 0;