Hi Vladis,
On Thu, Mar 30, 2017 at 12:27:12PM +0200, Vladis Dronov wrote:
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://urldefense.proofpoint.com/v2/url?u=https-3A__bugzilla.redhat.com_sho... Signed-off-by: Vladis Dronov vdronov@redhat.com
drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index b445ce9..b30824b 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -1281,6 +1281,10 @@ int vmw_gb_surface_define_ioctl(struct drm_device *dev, void *data, if (req->multisample_count != 0) return -EINVAL;
- if (req->mip_levels > DRM_VMW_MAX_SURFACE_FACES *
DRM_VMW_MAX_MIP_LEVELS)return -EINVAL;
Here, the check should be "> DRM_VMW_MAX_MIP_LEVELS" because req->mip_levels is only for one layer.
Also, as long as we can doing a check, I would suggest we check for 0 as well.
Sinclair