net: Fix skb csum races when peeking

[pandora-kernel.git] / net / core / datagram.c

diff --git a/net/core/datagram.c b/net/core/datagram.c
index 4e9a3f6..4967262 100644 (file)
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -657,7 +657,8 @@ __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len)
                    !skb->csum_complete_sw)
                        netdev_rx_csum_fault(skb->dev);
        }
-       skb->csum_valid = !sum;
+       if (!skb_shared(skb))
+               skb->csum_valid = !sum;
        return sum;
 }
 EXPORT_SYMBOL(__skb_checksum_complete_head);
@@ -677,11 +678,13 @@ __sum16 __skb_checksum_complete(struct sk_buff *skb)
                        netdev_rx_csum_fault(skb->dev);
        }
 
-       /* Save full packet checksum */
-       skb->csum = csum;
-       skb->ip_summed = CHECKSUM_COMPLETE;
-       skb->csum_complete_sw = 1;
-       skb->csum_valid = !sum;
+       if (!skb_shared(skb)) {
+               /* Save full packet checksum */
+               skb->csum = csum;
+               skb->ip_summed = CHECKSUM_COMPLETE;
+               skb->csum_complete_sw = 1;
+               skb->csum_valid = !sum;
+       }
 
        return sum;
 }