[Acked][lucid/fsl-imx51, maverick, maverick/ti-omap4, natty/ti-omap4 CVE 1/1] can: Add missing socket check in can/bcm release.

[Stefan Bader]

On 13.06.2011 12:58, Andy Whitcroft wrote:
> From: Dave Jones <davej at redhat.com>
> 
> We can get here with a NULL socket argument passed from userspace,
> so we need to handle it accordingly.
> 
> Signed-off-by: Dave Jones <davej at redhat.com>
> Signed-off-by: David S. Miller <davem at davemloft.net>
> 
> (cherry picked from commit c6914a6f261aca0c9f715f883a353ae7ff51fe83)
> CVE-2011-1598
> BugLink: http://bugs.launchpad.net/bugs/796502
> Signed-off-by: Andy Whitcroft <apw at canonical.com>
> ---
>  net/can/bcm.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/net/can/bcm.c b/net/can/bcm.c
> index 9d5e8ac..56d20a2 100644
> --- a/net/can/bcm.c
> +++ b/net/can/bcm.c
> @@ -1424,9 +1424,14 @@ static int bcm_init(struct sock *sk)
>  static int bcm_release(struct socket *sock)
>  {
>  	struct sock *sk = sock->sk;
> -	struct bcm_sock *bo = bcm_sk(sk);
> +	struct bcm_sock *bo;
>  	struct bcm_op *op, *next;
>  
> +	if (sk == NULL)
> +		return 0;
> +
> +	bo = bcm_sk(sk);
> +
>  	/* remove bcm_ops, timer, rx_unregister(), etc. */
>  
>  	unregister_netdevice_notifier(&bo->notifier);

Acked-by: Stefan Bader <stefan.bader at canonical.com>