Re: [v2.6.34-stable 032/213] ipvs: fix info leak ingetsockopt(IP_VS_SO_GET_TIMEOUT)

[Julian Anastasov]

	Hello,

On Wed, 5 Feb 2014, Paul Gortmaker wrote:

> From: Mathias Krause <minipli@xxxxxxxxxxxxxx>
> 
>                    -------------------
>     This is a commit scheduled for the next v2.6.34 longterm release.
>     http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
>     If you see a problem with using this for longterm, please comment.
>                    -------------------
> 
> commit 2d8a041b7bfe1097af21441cb77d6af95f4f4680 upstream.
> 
> If at least one of CONFIG_IP_VS_PROTO_TCP or CONFIG_IP_VS_PROTO_UDP is
> not set, __ip_vs_get_timeouts() does not fully initialize the structure
> that gets copied to userland and that for leaks up to 12 bytes of kernel
> stack. Add an explicit memset(0) before passing the structure to
> __ip_vs_get_timeouts() to avoid the info leak.

	I guess, this patch is not needed after commit
"ipvs: initialize returned data in do_ip_vs_get_ctl" because
the memset is already moved into __ip_vs_get_timeouts().

> Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
> Cc: Wensong Zhang <wensong@xxxxxxxxxxxx>
> Cc: Simon Horman <horms@xxxxxxxxxxxx>
> Cc: Julian Anastasov <ja@xxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
> ---
>  net/netfilter/ipvs/ip_vs_ctl.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index 36dc1d88c2fa..bd9d805a85a6 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
> @@ -2469,6 +2469,7 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
>  	{
>  		struct ip_vs_timeout_user t;
>  
> +		memset(&t, 0, sizeof(t));
>  		__ip_vs_get_timeouts(&t);
>  		if (copy_to_user(user, &t, sizeof(t)) != 0)
>  			ret = -EFAULT;
> -- 
> 1.8.5.2

Regards

--
Julian Anastasov <ja@xxxxxx>
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