2017-08-02 18:00:26

by David Lechner

Subject: [PATCH] drm/fb: Fix pointer dereference before null check.

fb_crtc is used before a null check, so move the use after the null check.

This was just identified by inspection. I haven't actually observed a crash
here, so it is possible that the null check could be unnecessary.

Signed-off-by: David Lechner <[email protected]>
---
drivers/gpu/drm/drm_fb_helper.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 2cc28f0..2d3f93e 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2424,9 +2424,9 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
struct drm_display_mode *mode = modes[i];
struct drm_fb_helper_crtc *fb_crtc = crtcs[i];
struct drm_fb_offset *offset = &offsets[i];
- struct drm_mode_set *modeset = &fb_crtc->mode_set;

if (mode && fb_crtc) {
+ struct drm_mode_set *modeset = &fb_crtc->mode_set;
struct drm_connector *connector =
fb_helper->connector_info[i]->connector;

--
2.7.4

2017-08-03 10:12:38

by Daniel Vetter

Subject: Re: [PATCH] drm/fb: Fix pointer dereference before null check.

On Wed, Aug 02, 2017 at 01:00:13PM -0500, David Lechner wrote:
> fb_crtc is used before a null check, so move the use after the null check.
>
> This was just identified by inspection. I haven't actually observed a crash
> here, so it is possible that the null check could be unnecessary.
>
> Signed-off-by: David Lechner <[email protected]>

Thanks, applied.
-Daniel

> ---
> drivers/gpu/drm/drm_fb_helper.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 2cc28f0..2d3f93e 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -2424,9 +2424,9 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
> struct drm_display_mode *mode = modes[i];
> struct drm_fb_helper_crtc *fb_crtc = crtcs[i];
> struct drm_fb_offset *offset = &offsets[i];
> - struct drm_mode_set *modeset = &fb_crtc->mode_set;
>
> if (mode && fb_crtc) {
> + struct drm_mode_set *modeset = &fb_crtc->mode_set;
> struct drm_connector *connector =
> fb_helper->connector_info[i]->connector;
>
> --
> 2.7.4
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch