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

commit 1922756 upstream. This fixes CVE-2011-1013. Reported-by: Matthiew Herrb (OpenBSD X.org team) Signed-off-by: Dave Airlie <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Andi Kleen <[email protected]>
TheEscapist13 · Mar 31, 2011 · ef7626e · ef7626e
1 parent 065d369
commit ef7626e
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Showing 2 changed files with 3 additions and 2 deletions.
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
@@ -545,7 +545,8 @@ 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
@@ -1021,7 +1021,7 @@ struct drm_device {
 	struct pci_controller *hose;
 #endif
 	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;