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authorEric Dumazet <eric.dumazet@gmail.com>2012-02-23 10:55:02 +0000
committerDavid S. Miller <davem@davemloft.net>2012-02-23 16:50:45 -0500
commit03606895cd98c0a628b17324fd7b5ff15db7e3cd (patch)
tree26aab95243f23a5d0cff45ee0d6afd1608afe5df
parent4a2258ddddefeef3291c0fc66437c73d84261a1e (diff)
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>
-rw-r--r--include/linux/skbuff.h10
-rw-r--r--net/ipv4/xfrm4_mode_beet.c5
-rw-r--r--net/ipv4/xfrm4_mode_tunnel.c6
-rw-r--r--net/ipv6/xfrm6_mode_beet.c6
-rw-r--r--net/ipv6/xfrm6_mode_tunnel.c6
5 files changed, 16 insertions, 17 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 50db9b04a552..ae86adee3746 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1465,6 +1465,16 @@ static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
}
#endif /* NET_SKBUFF_DATA_USES_OFFSET */
+static inline void skb_mac_header_rebuild(struct sk_buff *skb)
+{
+ if (skb_mac_header_was_set(skb)) {
+ const unsigned char *old_mac = skb_mac_header(skb);
+
+ skb_set_mac_header(skb, -skb->mac_len);
+ memmove(skb_mac_header(skb), old_mac, skb->mac_len);
+ }
+}
+
static inline int skb_checksum_start_offset(const struct sk_buff *skb)
{
return skb->csum_start - skb_headroom(skb);
diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c
index 63418185f524..e3db3f915114 100644
--- a/net/ipv4/xfrm4_mode_beet.c
+++ b/net/ipv4/xfrm4_mode_beet.c
@@ -110,10 +110,7 @@ static int xfrm4_beet_input(struct xfrm_state *x, struct sk_buff *skb)
skb_push(skb, sizeof(*iph));
skb_reset_network_header(skb);
-
- memmove(skb->data - skb->mac_len, skb_mac_header(skb),
- skb->mac_len);
- skb_set_mac_header(skb, -skb->mac_len);
+ skb_mac_header_rebuild(skb);
xfrm4_beet_make_header(skb);
diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index 534972e114ac..ed4bf11ef9f4 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -66,7 +66,6 @@ static int xfrm4_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
- const unsigned char *old_mac;
int err = -EINVAL;
if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
@@ -84,10 +83,9 @@ static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip_ecn_decapsulate(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_reset_network_header(skb);
+ skb_mac_header_rebuild(skb);
+
err = 0;
out:
diff --git a/net/ipv6/xfrm6_mode_beet.c b/net/ipv6/xfrm6_mode_beet.c
index a81ce9450750..9949a356d62c 100644
--- a/net/ipv6/xfrm6_mode_beet.c
+++ b/net/ipv6/xfrm6_mode_beet.c
@@ -80,7 +80,6 @@ static int xfrm6_beet_output(struct xfrm_state *x, struct sk_buff *skb)
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 @@ static int xfrm6_beet_input(struct xfrm_state *x, struct sk_buff *skb)
__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);
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index 261e6e6f487e..9f2095b19ad0 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -63,7 +63,6 @@ static int xfrm6_mode_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
{
int err = -EINVAL;
- const unsigned char *old_mac;
if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
goto out;
@@ -80,10 +79,9 @@ static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
if (!(x->props.flags & XFRM_STATE_NOECN))
ipip6_ecn_decapsulate(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_reset_network_header(skb);
+ skb_mac_header_rebuild(skb);
+
err = 0;
out: