From patchwork Tue Sep 13 16:48:44 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [lucid/fsl-imx51, maverick, maverick/ti-omap4, natty, natty/ti-omap4, CVE, 1/1] gro: Only reset frag0 when skb can be pulled From: Andy Whitcroft X-Patchwork-Id: 114512 Message-Id: <1315932524-6144-2-git-send-email-apw@canonical.com> To: kernel-team@lists.ubuntu.com Cc: Andy Whitcroft Date: Tue, 13 Sep 2011 17:48:44 +0100 From: Herbert Xu Currently skb_gro_header_slow unconditionally resets frag0 and frag0_len. However, when we can't pull on the skb this leaves the GRO fields in an inconsistent state. This patch fixes this by only resetting those fields after the pskb_may_pull test. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller (cherry picked from commit 17dd759c67f21e34f2156abcf415e1f60605a188) CVE-2011-2723 BugLink: http://bugs.launchpad.net/bugs/844371 Signed-off-by: Andy Whitcroft --- include/linux/netdevice.h | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d4a4d98..b337b81 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1152,9 +1152,12 @@ static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen) static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen, unsigned int offset) { + if (!pskb_may_pull(skb, hlen)) + return NULL; + NAPI_GRO_CB(skb)->frag0 = NULL; NAPI_GRO_CB(skb)->frag0_len = 0; - return pskb_may_pull(skb, hlen) ? skb->data + offset : NULL; + return skb->data + offset; } static inline void *skb_gro_mac_header(struct sk_buff *skb)