[NET]: Avoid copying writable clones in tunnel drivers
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 1efa95a..eb20bb6 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -532,7 +532,8 @@
*/
max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
- if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
+ if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
+ (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
if (!new_skb) {
ip_rt_put(rt);