drm: fix unsigned vs signed comparison issue in modeset ctl ioctl.

This fixes CVE-2011-1013.

Reported-by: Matthiew Herrb (OpenBSD X.org team)
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 3 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 53120a72a48..28d1d3c24d6 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1012,7 +1012,8 @@ int drm_modeset_ctl(struct drm_device *dev, void *data,
                     struct drm_file *file_priv)
 {
         struct drm_modeset_ctl *modeset = data;
-        int crtc, ret = 0;
+        int ret = 0;
+        unsigned int crtc;
 
         /* If drm_vblank_init() hasn't been called yet, just no-op */
         if (!dev->num_crtcs)
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index fe29aadb129..348843b8015 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1101,7 +1101,7 @@ struct drm_device {
         struct platform_device *platformdev; /**< Platform device struture */
 
         struct drm_sg_mem *sg;  /**< Scatter gather memory */
-        int num_crtcs;                  /**< Number of CRTCs on this device */
+        unsigned int num_crtcs;                  /**< Number of CRTCs on this device */
         void *dev_private;              /**< device private data */
         void *mm_private;
         struct address_space *dev_mapping;