From a19faf0250e09b16cac169354126404bc8aa342b Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sun, 5 Dec 2010 18:50:32 +0000
Subject: [PATCH] net: fix skb_defer_rx_timestamp()
After commit c1f19b51d1d8 (net: support time stamping in phy devices.),
kernel might crash if CONFIG_NETWORK_PHY_TIMESTAMPING=y and
skb_defer_rx_timestamp() handles a packet without an ethernet header.
Fixes kernel bugzilla #24102
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=24102
Reported-and-tested-by: Andrew Watts <akwatts@ymail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/core/timestamping.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/net/core/timestamping.c b/net/core/timestamping.c
index 0ae6c22da85b..c19bb4ee405e 100644
--- a/net/core/timestamping.c
+++ b/net/core/timestamping.c
@@ -96,11 +96,13 @@ bool skb_defer_rx_timestamp(struct sk_buff *skb)
struct phy_device *phydev;
unsigned int type;
- skb_push(skb, ETH_HLEN);
+ if (skb_headroom(skb) < ETH_HLEN)
+ return false;
+ __skb_push(skb, ETH_HLEN);
type = classify(skb);
- skb_pull(skb, ETH_HLEN);
+ __skb_pull(skb, ETH_HLEN);
switch (type) {
case PTP_CLASS_V1_IPV4:
--
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