[PATCH 4.4 42/67] net: pktgen: fix null ptr deref in skb allocation
From: Greg Kroah-Hartman
Date: Wed Jan 27 2016 - 15:28:24 EST
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: John Fastabend <john.fastabend@xxxxxxxxx>
[ Upstream commit 3de03596dfeee48bc803c1d1a6daf60a459929f3 ]
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@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/pktgen.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2787,7 +2787,9 @@ static struct sk_buff *pktgen_alloc_skb(
} 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;
}