6lowpan: Make a copy of skb's delivered to 6lowpan

Since lowpan_process_data() modifies the skb (by calling skb_pull()), we
need our own copy so that it doesn't affect the data received by other
protcols (in this case, af_ieee802154).

Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: David S. Miller <davem@tempietto.lan>

1 files changed, 8 insertions, 1 deletions

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 6a095225148e..b28ec790c7c8 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1133,6 +1133,8 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
         struct packet_type *pt, struct net_device *orig_dev)
 {
+        struct sk_buff *local_skb;
+
         if (!netif_running(dev))
                 goto drop;
 
@@ -1144,7 +1146,12 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
         case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
         case LOWPAN_DISPATCH_FRAG1:     /* first fragment header */
         case LOWPAN_DISPATCH_FRAGN:     /* next fragments headers */
-                lowpan_process_data(skb);
+                local_skb = skb_clone(skb, GFP_ATOMIC);
+                if (!local_skb)
+                        goto drop;
+                lowpan_process_data(local_skb);
+
+                kfree_skb(skb);
                 break;
         default:
                 break;