[ 057/180] ipsec: be careful of non existing mac headers
From: Willy Tarreau
Date: Mon Oct 01 2012 - 20:10:00 EST
2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <eric.dumazet@xxxxxxxxx>
[ Upstream commit 03606895cd98c0a628b17324fd7b5ff15db7e3cd ]
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@xxxxxxxxxxxxxxx>
Tested-by: Niccolò Belli <darkbasic@xxxxxxxxxxxxxxx>
Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Willy Tarreau <w@xxxxxx>
---
include/linux/skbuff.h | 10 ++++++++++
net/ipv4/xfrm4_mode_beet.c | 5 +----
net/ipv4/xfrm4_mode_tunnel.c | 6 ++----
net/ipv6/xfrm6_mode_beet.c | 6 +-----
net/ipv6/xfrm6_mode_tunnel.c | 6 ++----
5 files changed, 16 insertions(+), 17 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index bcdd660..4e647bb 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1312,6 +1312,16 @@ 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_transport_offset(const struct sk_buff *skb)
{
return skb_transport_header(skb) - skb->data;
diff --git a/net/ipv4/xfrm4_mode_beet.c b/net/ipv4/xfrm4_mode_beet.c
index 6341818..e3db3f9 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 3444f3b..5d1d1fd 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -65,7 +65,6 @@ 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)
@@ -83,10 +82,9 @@ 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 bbd48b1..6cc7a45 100644
--- a/net/ipv6/xfrm6_mode_beet.c
+++ b/net/ipv6/xfrm6_mode_beet.c
@@ -82,7 +82,6 @@ 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;
@@ -92,10 +91,7 @@ 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 3927832..672c0da 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -61,7 +61,6 @@ 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;
@@ -78,10 +77,9 @@ 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:
--
1.7.2.1.45.g54fbc
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