From: John Fastabend <john.fastabend@gmail.com>
Date: Mon, 11 Jan 2016 05:38:44 +0000 (-0800)
Subject: net: pktgen: fix null ptr deref in skb allocation
X-Git-Tag: v4.14-rc1~4003^2~24
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3de03596dfeee48bc803c1d1a6daf60a459929f3;p=platform%2Fkernel%2Flinux-rpi.git

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 de8d5cc..4da4d51 100644
--- 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;
 }