@@ -5590,6 +5590,7 @@ static void skb_mod_eth_type(struct sk_buff *skb, struct ethhdr *hdr,
int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
int mac_len, bool ethernet)
{
+ int offset = skb->data - skb_mac_header(skb);
struct mpls_shim_hdr *lse;
int err;
@@ -5600,6 +5601,9 @@ int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
if (skb->encapsulation)
return -EINVAL;
+ if (WARN_ONCE(offset, "We got skb with skb->data not at mac header (offset %d)\n", offset))
+ return -EINVAL;
+
err = skb_cow_head(skb, MPLS_HLEN);
if (unlikely(err))
return err;
@@ -5643,11 +5647,15 @@ EXPORT_SYMBOL_GPL(skb_mpls_push);
int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
bool ethernet)
{
+ int offset = skb->data - skb_mac_header(skb);
int err;
if (unlikely(!eth_p_mpls(skb->protocol)))
return 0;
+ if (WARN_ONCE(offset, "We got skb with skb->data not at mac header (offset %d)\n", offset))
+ return -EINVAL;
+
err = skb_ensure_writable(skb, mac_len + MPLS_HLEN);
if (unlikely(err))
return err;
skb_mpls_push() and skb_mpls_pop() expect skb->data at mac header. Check this assumption or we would get wrong mac_header and network_header. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- net/core/skbuff.c | 8 ++++++++ 1 file changed, 8 insertions(+)