ACK: [natty, natty/ti-omap4 CVE 1/1] TOMOYO: Fix oops in tomoyo_mount_acl().

[Stefan Bader]

On 06.02.2012 11:39, Andy Whitcroft wrote:
> From: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
> 
> In tomoyo_mount_acl() since 2.6.36, kern_path() was called without checking
> dev_name != NULL. As a result, an unprivileged user can trigger oops by issuing
> mount(NULL, "/", "ext3", 0, NULL) request.
> Fix this by checking dev_name != NULL before calling kern_path(dev_name).
> 
> Signed-off-by: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp>
> Cc: stable at kernel.org
> Signed-off-by: James Morris <jmorris at namei.org>
> 
> (cherry picked from commit 4e78c724d47e2342aa8fde61f6b8536f662f795f)
> CVE-2011-2518
> BugLink: http://bugs.launchpad.net/bugs/922377
> Signed-off-by: Andy Whitcroft <apw at canonical.com>
> ---
>  security/tomoyo/mount.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/security/tomoyo/mount.c b/security/tomoyo/mount.c
> index 82bf8c2..afa07cf 100644
> --- a/security/tomoyo/mount.c
> +++ b/security/tomoyo/mount.c
> @@ -138,7 +138,7 @@ static int tomoyo_mount_acl(struct tomoyo_request_info *r, char *dev_name,
>  	}
>  	if (need_dev) {
>  		/* Get mount point or device file. */
> -		if (kern_path(dev_name, LOOKUP_FOLLOW, &path)) {
> +		if (!dev_name || kern_path(dev_name, LOOKUP_FOLLOW, &path)) {
>  			error = -ENOENT;
>  			goto out;
>  		}

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