From 4b0ef1f223be4e092632b4152ceec5627ac10f59 Mon Sep 17 00:00:00 2001
From: Dang Hongwu <hongwu.dang@6wind.com>
Date: Tue, 11 Jan 2011 07:13:33 +0000
Subject: [PATCH] ah: reload pointers to skb data after calling skb_cow_data()
skb_cow_data() may allocate a new data buffer, so pointers on
skb should be set after this function.
Bug was introduced by commit dff3bb06 ("ah4: convert to ahash")
and 8631e9bd ("ah6: convert to ahash").
Signed-off-by: Wang Xuefu <xuefu.wang@6wind.com>
Acked-by: Krzysztof Witek <krzysztof.witek@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv4/ah4.c | 7 ++++---
net/ipv6/ah6.c | 8 +++++---
2 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 880a5ec6dce0..86961bec70ab 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -314,14 +314,15 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
skb->ip_summed = CHECKSUM_NONE;
- ah = (struct ip_auth_hdr *)skb->data;
- iph = ip_hdr(skb);
- ihl = ip_hdrlen(skb);
if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
goto out;
nfrags = err;
+ ah = (struct ip_auth_hdr *)skb->data;
+ iph = ip_hdr(skb);
+ ihl = ip_hdrlen(skb);
+
work_iph = ah_alloc_tmp(ahash, nfrags, ihl + ahp->icv_trunc_len);
if (!work_iph)
goto out;
diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index ee82d4ef26ce..1aba54ae53c4 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -538,14 +538,16 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
if (!pskb_may_pull(skb, ah_hlen))
goto out;
- ip6h = ipv6_hdr(skb);
-
- skb_push(skb, hdr_len);
if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
goto out;
nfrags = err;
+ ah = (struct ip_auth_hdr *)skb->data;
+ ip6h = ipv6_hdr(skb);
+
+ skb_push(skb, hdr_len);
+
work_iph = ah_alloc_tmp(ahash, nfrags, hdr_len + ahp->icv_trunc_len);
if (!work_iph)
goto out;
--
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