diff mbox

[1/1] GSO: Reload iph after pskb_may_pull

Message ID 20161128153658.GB4778@kernel.org
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Arnaldo Carvalho de Melo Nov. 28, 2016, 3:36 p.m. UTC 
As it may get stale and lead to use after free.

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Alexander Duyck <aduyck@mirantis.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Fixes: cbc53e08a793 ("GSO: Add GSO type for fixed IPv4 ID")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 net/ipv4/af_inet.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alexander H Duyck Nov. 28, 2016, 4:34 p.m. UTC | #1 
On Mon, Nov 28, 2016 at 7:36 AM, Arnaldo Carvalho de Melo
<acme@kernel.org> wrote:
> As it may get stale and lead to use after free.
>
> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
> Cc: Alexander Duyck <aduyck@mirantis.com>
> Cc: Andrey Konovalov <andreyknvl@google.com>
> Fixes: cbc53e08a793 ("GSO: Add GSO type for fixed IPv4 ID")
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>  net/ipv4/af_inet.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index 5ddf5cda07f4..215143246e4b 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -1233,7 +1233,7 @@ struct sk_buff *inet_gso_segment(struct sk_buff *skb,
>                 fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
>
>                 /* fixed ID is invalid if DF bit is not set */
> -               if (fixedid && !(iph->frag_off & htons(IP_DF)))
> +               if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
>                         goto out;
>         }
>
> --
> 2.9.3
>

Looks good to me.

Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
David Miller Nov. 30, 2016, 1:46 a.m. UTC | #2 
From: Arnaldo Carvalho de Melo <acme@kernel.org>
Date: Mon, 28 Nov 2016 12:36:58 -0300

> As it may get stale and lead to use after free.
> 
> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
> Cc: Alexander Duyck <aduyck@mirantis.com>
> Cc: Andrey Konovalov <andreyknvl@google.com>
> Fixes: cbc53e08a793 ("GSO: Add GSO type for fixed IPv4 ID")
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Applied and queued up for -stable, thanks Arnaldo!
diff mbox

Patch

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5ddf5cda07f4..215143246e4b 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1233,7 +1233,7 @@  struct sk_buff *inet_gso_segment(struct sk_buff *skb,
 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
 
 		/* fixed ID is invalid if DF bit is not set */
-		if (fixedid && !(iph->frag_off & htons(IP_DF)))
+		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
 			goto out;
 	}