diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2008-01-28 20:45:20 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-01-31 19:27:07 -0800 |
| commit | 29ffe1a5c52dae13b6efead97aab9b058f38fce4 (patch) | |
| tree | bcca1391f02a01cf1b2d5942a06d392ac0f5be11 | |
| parent | 1987e7b4855fcb6a866d3279ee9f2890491bc34d (diff) | |
[INET]: Prevent out-of-sync truesize on ip_fragment slow path
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 <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/ip_output.c | 4 | ||||
| -rw-r--r-- | net/ipv6/ip6_output.c | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 18070ca65771..6e4d5f493bf9 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -476,6 +476,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) 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) || @@ -499,7 +500,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) sock_hold(skb->sk); frag->sk = skb->sk; frag->destructor = sock_wfree; - skb->truesize -= frag->truesize; + truesizes += frag->truesize; } } @@ -510,6 +511,7 @@ int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff*)) 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); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 15c4f6cee3e6..cfe9e707883c 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -636,6 +636,7 @@ static int ip6_fragment(struct sk_buff *skb, int (*output)(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) || @@ -658,7 +659,7 @@ static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) sock_hold(skb->sk); frag->sk = skb->sk; frag->destructor = sock_wfree; - skb->truesize -= frag->truesize; + truesizes += frag->truesize; } } @@ -689,6 +690,7 @@ static int ip6_fragment(struct sk_buff *skb, int (*output)(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)); |