Patchwork [lucid/fsl-imx51,maverick,maverick/ti-omap4,natty,natty/ti-omap4,CVE,1/1] gro: Only reset frag0 when skb can be pulled

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Submitter Andy Whitcroft
Date Sept. 13, 2011, 4:48 p.m.
Message ID <1315932524-6144-2-git-send-email-apw@canonical.com>
Download mbox | patch
Permalink /patch/114512/
State New
Headers show

Comments

Andy Whitcroft - Sept. 13, 2011, 4:48 p.m.
From: Herbert Xu <herbert@gondor.apana.org.au>

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 <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit 17dd759c67f21e34f2156abcf415e1f60605a188)
CVE-2011-2723
BugLink: http://bugs.launchpad.net/bugs/844371
Signed-off-by: Andy Whitcroft <apw@canonical.com>
---
 include/linux/netdevice.h |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

Patch

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)