[PATCH] drm, video: fix use-before-NULL-check

Kees Cook kees.cook at canonical.com
Fri Aug 27 14:07:19 PDT 2010


Fix potential crashes due to use-before-NULL situations.

Signed-off-by: Kees Cook <kees.cook at canonical.com>
---
 drivers/gpu/drm/drm_fb_helper.c           |    3 ++-
 drivers/media/video/em28xx/em28xx-video.c |    3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index de82e20..8dd7e6f 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -94,10 +94,11 @@ static bool drm_fb_helper_connector_parse_command_line(struct drm_fb_helper_conn
 	int i;
 	enum drm_connector_force force = DRM_FORCE_UNSPECIFIED;
 	struct drm_fb_helper_cmdline_mode *cmdline_mode;
-	struct drm_connector *connector = fb_helper_conn->connector;
+	struct drm_connector *connector;
 
 	if (!fb_helper_conn)
 		return false;
+	connector = fb_helper_conn->connector;
 
 	cmdline_mode = &fb_helper_conn->cmdline_mode;
 	if (!mode_option)
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index 7b9ec6e..95a4b60 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -277,12 +277,13 @@ static void em28xx_copy_vbi(struct em28xx *dev,
 {
 	void *startwrite, *startread;
 	int  offset;
-	int bytesperline = dev->vbi_width;
+	int bytesperline;
 
 	if (dev == NULL) {
 		em28xx_isocdbg("dev is null\n");
 		return;
 	}
+	bytesperline = dev->vbi_width;
 
 	if (dma_q == NULL) {
 		em28xx_isocdbg("dma_q is null\n");
-- 
1.7.1


-- 
Kees Cook
Ubuntu Security Team


More information about the dri-devel mailing list