Re: [PATCH] ipvs: Keep skb->sk when allocating headroom on tunnel xmit

To: Julian Anastasov <ja@xxxxxx>
Subject: Re: [PATCH] ipvs: Keep skb->sk when allocating headroom on tunnel xmit
Cc: Simon Horman <horms@xxxxxxxxxxxx>, Wensong Zhang <wensong@xxxxxxxxxxxx>, <lvs-devel@xxxxxxxxxxxxxxx>, <linux-kernel@xxxxxxxxxxxxxxx>, <netdev@xxxxxxxxxxxxxxx>, <agartrell@xxxxxx>, <kernel-team@xxxxxx>
From: Calvin Owens <calvinowens@xxxxxx>
Date: Fri, 7 Nov 2014 14:12:13 -0800
On 11/05/2014 01:21 AM, Julian Anastasov wrote:


On Tue, 4 Nov 2014, Calvin Owens wrote:

ip_vs_prepare_tunneled_skb() ignores ->sk when allocating a new
skb, either unconditionally setting ->sk to NULL or allowing
the uninitialized ->sk from a newly allocated skb to leak through
to the caller.

This patch properly copies ->sk and increments its reference count.

Signed-off-by: Calvin Owens <calvinowens@xxxxxx>

        Good catch. Please, extend your patch to
fix also the second place that has such error,
ip_vs_tunnel_xmit_v6. This call is missing from long time,
it was not needed. But commits that allow skb->sk (local
clients) already need it, eg.

I'm not sure where exactly you mean: ip_vs_tunnel_xmit_v6() calls
ip_vs_prepare_tunneled_skb() to do the allocation, so this patch covers that case.

In older versions of the kernel, ip_vs_tunnel_xmit_v6() does it directly, could that be what you're looking at?

- f2428ed5e7bc89c7 ("ipvs: load balance ipv6 connections from a local
process"), 2.6.28
- 4856c84c1358b798 ("ipvs: load balance IPv4 connections from a local
process"), 2.6.28

  net/netfilter/ipvs/ip_vs_xmit.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 437a366..bd90bf8 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -846,6 +846,8 @@ ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af,
                new_skb = skb_realloc_headroom(skb, max_headroom);
                if (!new_skb)
                        goto error;
+               if (skb->sk)
+                       skb_set_owner_w(new_skb, skb->sk);
                skb = new_skb;


Julian Anastasov <ja@xxxxxx>

To unsubscribe from this list: send the line "unsubscribe lvs-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at

<Prev in Thread] Current Thread [Next in Thread>