2.6.24-stable review patch.  If anyone has any objections, please let us
know.

------------------
Upstream commit: 29ffe1a5c52dae13b6efead97aab9b058f38fce4

When ip_fragment has to hit the slow path the value of skb->truesize
may go out of sync because we would have updated it without changing
the packet length.  This violates the constraints on truesize.

This patch postpones the update of skb->truesize to prevent this.

Signed-off-by: Herbert Xu <[EMAIL PROTECTED]>
Signed-off-by: David S. Miller <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>

---
 net/ipv4/ip_output.c  |    4 +++-
 net/ipv6/ip6_output.c |    4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -462,6 +462,7 @@ int ip_fragment(struct sk_buff *skb, int
        if (skb_shinfo(skb)->frag_list) {
                struct sk_buff *frag;
                int first_len = skb_pagelen(skb);
+               int truesizes = 0;
 
                if (first_len - hlen > mtu ||
                    ((first_len - hlen) & 7) ||
@@ -485,7 +486,7 @@ int ip_fragment(struct sk_buff *skb, int
                                sock_hold(skb->sk);
                                frag->sk = skb->sk;
                                frag->destructor = sock_wfree;
-                               skb->truesize -= frag->truesize;
+                               truesizes += frag->truesize;
                        }
                }
 
@@ -496,6 +497,7 @@ int ip_fragment(struct sk_buff *skb, int
                frag = skb_shinfo(skb)->frag_list;
                skb_shinfo(skb)->frag_list = NULL;
                skb->data_len = first_len - skb_headlen(skb);
+               skb->truesize -= truesizes;
                skb->len = first_len;
                iph->tot_len = htons(first_len);
                iph->frag_off = htons(IP_MF);
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -609,6 +609,7 @@ static int ip6_fragment(struct sk_buff *
 
        if (skb_shinfo(skb)->frag_list) {
                int first_len = skb_pagelen(skb);
+               int truesizes = 0;
 
                if (first_len - hlen > mtu ||
                    ((first_len - hlen) & 7) ||
@@ -631,7 +632,7 @@ static int ip6_fragment(struct sk_buff *
                                sock_hold(skb->sk);
                                frag->sk = skb->sk;
                                frag->destructor = sock_wfree;
-                               skb->truesize -= frag->truesize;
+                               truesizes += frag->truesize;
                        }
                }
 
@@ -662,6 +663,7 @@ static int ip6_fragment(struct sk_buff *
 
                first_len = skb_pagelen(skb);
                skb->data_len = first_len - skb_headlen(skb);
+               skb->truesize -= truesizes;
                skb->len = first_len;
                ipv6_hdr(skb)->payload_len = htons(first_len -
                                                   sizeof(struct ipv6hdr));

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