From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pravin B Shelar , Li RongQing , "David S. Miller" Subject: [PATCH 3.17 009/319] ipv4: fix a potential use after free in ip_tunnel_core.c Date: Wed, 12 Nov 2014 10:12:27 +0900 Message-Id: <20141112010954.206722530@linuxfoundation.org> In-Reply-To: <20141112010952.553519040@linuxfoundation.org> References: <20141112010952.553519040@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li RongQing [ Upstream commit 1245dfc8cadb258386fcd27df38215a0eccb1f17 ] pskb_may_pull() maybe change skb->data and make eth pointer oboslete, so set eth after pskb_may_pull() Fixes:3d7b46cd("ip_tunnel: push generic protocol handling to ip_tunnel module") Cc: Pravin B Shelar Signed-off-by: Li RongQing Acked-by: Pravin B Shelar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_tunnel_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -91,11 +91,12 @@ int iptunnel_pull_header(struct sk_buff skb_pull_rcsum(skb, hdr_len); if (inner_proto == htons(ETH_P_TEB)) { - struct ethhdr *eh = (struct ethhdr *)skb->data; + struct ethhdr *eh; if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) return -ENOMEM; + eh = (struct ethhdr *)skb->data; if (likely(ntohs(eh->h_proto) >= ETH_P_802_3_MIN)) skb->protocol = eh->h_proto; else