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-rw-r--r--include/linux/skbuff.h3
-rw-r--r--net/core/dev.c5
-rw-r--r--net/ipv4/ip_output.c1
-rw-r--r--net/openvswitch/datapath.c5
-rw-r--r--net/xfrm/xfrm_output.c2
5 files changed, 11 insertions, 5 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 07f9ccd28654..11f935c1a090 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -3551,7 +3551,8 @@ struct skb_gso_cb {
int encap_level;
__u16 csum_start;
};
-#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
+#define SKB_SGO_CB_OFFSET 32
+#define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index 0ca95d5d7af0..cc9e3652cf93 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2695,6 +2695,8 @@ static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
*
* It may return NULL if the skb requires no segmentation. This is
* only possible when GSO is used for verifying header integrity.
+ *
+ * Segmentation preserves SKB_SGO_CB_OFFSET bytes of previous skb cb.
*/
struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
netdev_features_t features, bool tx_path)
@@ -2709,6 +2711,9 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
return ERR_PTR(err);
}
+ BUILD_BUG_ON(SKB_SGO_CB_OFFSET +
+ sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
+
SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
SKB_GSO_CB(skb)->encap_level = 0;
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 512a44778cf2..64878efa045c 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -239,6 +239,7 @@ static int ip_finish_output_gso(struct net *net, struct sock *sk,
* from host network stack.
*/
features = netif_skb_features(skb);
+ BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
if (IS_ERR_OR_NULL(segs)) {
kfree_skb(skb);
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 91a8b004dc51..deadfdab1bc3 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -336,12 +336,10 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
unsigned short gso_type = skb_shinfo(skb)->gso_type;
struct sw_flow_key later_key;
struct sk_buff *segs, *nskb;
- struct ovs_skb_cb ovs_cb;
int err;
- ovs_cb = *OVS_CB(skb);
+ BUILD_BUG_ON(sizeof(*OVS_CB(skb)) > SKB_SGO_CB_OFFSET);
segs = __skb_gso_segment(skb, NETIF_F_SG, false);
- *OVS_CB(skb) = ovs_cb;
if (IS_ERR(segs))
return PTR_ERR(segs);
if (segs == NULL)
@@ -359,7 +357,6 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
/* Queue all of the segments. */
skb = segs;
do {
- *OVS_CB(skb) = ovs_cb;
if (gso_type & SKB_GSO_UDP && skb != segs)
key = &later_key;
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index cc3676eb6239..ff4a91fcab9f 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -167,6 +167,8 @@ static int xfrm_output_gso(struct net *net, struct sock *sk, struct sk_buff *skb
{
struct sk_buff *segs;
+ BUILD_BUG_ON(sizeof(*IPCB(skb)) > SKB_SGO_CB_OFFSET);
+ BUILD_BUG_ON(sizeof(*IP6CB(skb)) > SKB_SGO_CB_OFFSET);
segs = skb_gso_segment(skb, 0);
kfree_skb(skb);
if (IS_ERR(segs))