From a19faf0250e09b16cac169354126404bc8aa342b Mon Sep 17 00:00:00 2001 From: Eric Dumazet 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 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- 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: -- 2.20.1