[Acked] [Quantal CVE-2013-3222] atm: update msg_namelen in vcc_recvmsg()

[Andy Whitcroft]

On Thu, May 09, 2013 at 11:01:40AM +0100, Luis Henriques wrote:
> From: Mathias Krause <minipli at googlemail.com>
> 
> CVE-2013-3222
> 
> BugLink: https://bugs.launchpad.net/bugs/1172365
> 
> The current code does not fill the msg_name member in case it is set.
> It also does not set the msg_namelen member to 0 and therefore makes
> net/socket.c leak the local, uninitialized sockaddr_storage variable
> to userland -- 128 bytes of kernel stack memory.
> 
> Fix that by simply setting msg_namelen to 0 as obviously nobody cared
> about vcc_recvmsg() not filling the msg_name in case it was set.
> 
> Signed-off-by: Mathias Krause <minipli at googlemail.com>
> Signed-off-by: David S. Miller <davem at davemloft.net>
> (cherry picked from commit 9b3e617f3df53822345a8573b6d358f6b9e5ed87)
> 
> Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
> ---
>  net/atm/common.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/atm/common.c b/net/atm/common.c
> index 806fc0a..cf4b7e6 100644
> --- a/net/atm/common.c
> +++ b/net/atm/common.c
> @@ -532,6 +532,8 @@ int vcc_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
>  	struct sk_buff *skb;
>  	int copied, error = -EINVAL;
>  
> +	msg->msg_namelen = 0;
> +
>  	if (sock->state != SS_CONNECTED)
>  		return -ENOTCONN;

Looks to be a cherry-pick indeed, and to do what is claimed.

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw