ACK: [CVE-2017-7346][PATCH Trusty] drm/vmwgfx: limit the number of mip levels in vmw_gb_surface_define_ioctl()

[Seth Forshee]

On Wed, Jun 14, 2017 at 05:09:34PM +0800, Po-Hsu Lin wrote:
> From: Vladis Dronov <vdronov at redhat.com>
> 
> CVE-2017-7346
> 
> The 'req->mip_levels' parameter in vmw_gb_surface_define_ioctl() is
> a user-controlled 'uint32_t' value which is used as a loop count limit.
> This can lead to a kernel lockup and DoS. Add check for 'req->mip_levels'.
> 
> References:
> https://bugzilla.redhat.com/show_bug.cgi?id=1437431
> 
> Cc: <stable at vger.kernel.org>
> Signed-off-by: Vladis Dronov <vdronov at redhat.com>
> Reviewed-by: Sinclair Yeh <syeh at vmware.com>
> (backported from commit ee9c4e681ec4f58e42a83cb0c22a0289ade1aacf)
> 
> Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>

Backport looks reasonable.

Acked-by: Seth Forshee <seth.forshee at canonical.com>