2015-08-31 04:01:15

by Jianwei Wang

Subject: [PATCH] drm/fsl-dcu: Fix no fb check bug

For state->fb may be NULL in fsl_dcu_drm_plane_atomic_check function,
if so, return -EINVAL. No need check in fsl_dcu_drm_plane_atomic_update
anymore.

Signed-off-by: Jianwei Wang <[email protected]>
---
drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
index 82be6b8..8787920 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
@@ -41,6 +41,9 @@ static int fsl_dcu_drm_plane_atomic_check(struct drm_plane *plane,
{
struct drm_framebuffer *fb = state->fb;

+ if (!fb)
+ return -EINVAL;
+
switch (fb->pixel_format) {
case DRM_FORMAT_RGB565:
case DRM_FORMAT_RGB888:
@@ -84,9 +87,6 @@ static void fsl_dcu_drm_plane_atomic_update(struct drm_plane *plane,
unsigned int alpha, bpp;
int index, ret;

- if (!fb)
- return;
-
index = fsl_dcu_drm_plane_index(plane);
if (index < 0)
return;
--
2.1.0.27.g96db324

2015-11-16 22:35:38

by Stefan Agner

Subject: Re: [PATCH] drm/fsl-dcu: Fix no fb check bug

Hi,

This avoids a NULL pointer dereference when no crtc is available (e.g.
the fsl,panel not assigned).

Any chance to get this into 4.4?

Tested-by: Stefan Agner <[email protected]>

--
Stefan

On 2015-08-30 20:39, Jianwei Wang wrote:
> For state->fb may be NULL in fsl_dcu_drm_plane_atomic_check function,
> if so, return -EINVAL. No need check in fsl_dcu_drm_plane_atomic_update
> anymore.
>
> Signed-off-by: Jianwei Wang <[email protected]>
> ---
> drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
> b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
> index 82be6b8..8787920 100644
> --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
> +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
> @@ -41,6 +41,9 @@ static int fsl_dcu_drm_plane_atomic_check(struct
> drm_plane *plane,
> {
> struct drm_framebuffer *fb = state->fb;
>
> + if (!fb)
> + return -EINVAL;
> +
> switch (fb->pixel_format) {
> case DRM_FORMAT_RGB565:
> case DRM_FORMAT_RGB888:
> @@ -84,9 +87,6 @@ static void fsl_dcu_drm_plane_atomic_update(struct
> drm_plane *plane,
> unsigned int alpha, bpp;
> int index, ret;
>
> - if (!fb)
> - return;
> -
> index = fsl_dcu_drm_plane_index(plane);
> if (index < 0)
> return;