net: pktgen: fix null ptr deref in skb allocation

Fix possible null pointer dereference that may occur when calling
skb_reserve() on a null skb.

Fixes: 879c7220e82 ("net: pktgen: Observe needed_headroom of the device")
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index de8d5cc5eb240555e2c8b30da7858b3ff9eadffb..4da4d51a2ccfd6e8b8833c35cc0604991536ed68 100644 (file)
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2787,7 +2787,9 @@ static struct sk_buff *pktgen_alloc_skb(struct net_device *dev,
        } else {
                 skb = __netdev_alloc_skb(dev, size, GFP_NOWAIT);
        }
-       skb_reserve(skb, LL_RESERVED_SPACE(dev));
+
+       if (likely(skb))
+               skb_reserve(skb, LL_RESERVED_SPACE(dev));
 
        return skb;
 }