ipsec: be careful of non existing mac headers
Niccolo Belli reported ipsec crashes in case we handle a frame without
mac header (atm in his case)
Before copying mac header, better make sure it is present.
Bugzilla reference: https://bugzilla.kernel.org/show_bug.cgi?id=42809
Reported-by: Niccolò Belli <darkbasic@linuxsystems.it>
Tested-by: Niccolò Belli <darkbasic@linuxsystems.it>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/xfrm6_mode_beet.c b/net/ipv6/xfrm6_mode_beet.c
index a81ce94..9949a35 100644
--- a/net/ipv6/xfrm6_mode_beet.c
+++ b/net/ipv6/xfrm6_mode_beet.c
@@ -80,7 +80,6 @@
static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipv6hdr *ip6h;
- const unsigned char *old_mac;
int size = sizeof(struct ipv6hdr);
int err;
@@ -90,10 +89,7 @@
__skb_push(skb, size);
skb_reset_network_header(skb);
-
- old_mac = skb_mac_header(skb);
- skb_set_mac_header(skb, -skb->mac_len);
- memmove(skb_mac_header(skb), old_mac, skb->mac_len);
+ skb_mac_header_rebuild(skb);
xfrm6_beet_make_header(skb);