2022-05-18 04:31:53

by Yuanjun Gong

Subject: [PATCH 1/1] radeon: fix a possible null pointer dereference

From: Gong Yuanjun <[email protected]>

In radeon_fp_native_mode(), the return value of drm_mode_duplicate()
is assigned to mode, which will lead to a NULL pointer dereference
on failure of drm_mode_duplicate(). Add a check to avoid npd.

The failure status of drm_cvt_mode() on the other path is checked too.

Signed-off-by: Gong Yuanjun <[email protected]>
---
drivers/gpu/drm/radeon/radeon_connectors.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index 0cb1345c6ba4..fabe4f4ca124 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -473,6 +473,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode
native_mode->vdisplay != 0 &&
native_mode->clock != 0) {
mode = drm_mode_duplicate(dev, native_mode);
+ if (!mode)
+ return NULL;
mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
drm_mode_set_name(mode);

@@ -487,6 +489,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode
* simpler.
*/
mode = drm_cvt_mode(dev, native_mode->hdisplay, native_mode->vdisplay, 60, true, false, false);
+ if (!mode)
+ return NULL;
mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
DRM_DEBUG_KMS("Adding cvt approximation of native panel mode %s\n", mode->name);
}
--
2.17.1

2022-05-18 04:55:03

by Alex Deucher

Subject: Re: [PATCH 1/1] radeon: fix a possible null pointer dereference

Applied. Thanks!

On Tue, May 17, 2022 at 9:13 AM Yuanjun Gong <[email protected]> wrote:
>
> From: Gong Yuanjun <[email protected]>
>
> In radeon_fp_native_mode(), the return value of drm_mode_duplicate()
> is assigned to mode, which will lead to a NULL pointer dereference
> on failure of drm_mode_duplicate(). Add a check to avoid npd.
>
> The failure status of drm_cvt_mode() on the other path is checked too.
>
> Signed-off-by: Gong Yuanjun <[email protected]>
> ---
> drivers/gpu/drm/radeon/radeon_connectors.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
> index 0cb1345c6ba4..fabe4f4ca124 100644
> --- a/drivers/gpu/drm/radeon/radeon_connectors.c
> +++ b/drivers/gpu/drm/radeon/radeon_connectors.c
> @@ -473,6 +473,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode
> native_mode->vdisplay != 0 &&
> native_mode->clock != 0) {
> mode = drm_mode_duplicate(dev, native_mode);
> + if (!mode)
> + return NULL;
> mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
> drm_mode_set_name(mode);
>
> @@ -487,6 +489,8 @@ static struct drm_display_mode *radeon_fp_native_mode(struct drm_encoder *encode
> * simpler.
> */
> mode = drm_cvt_mode(dev, native_mode->hdisplay, native_mode->vdisplay, 60, true, false, false);
> + if (!mode)
> + return NULL;
> mode->type = DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER;
> DRM_DEBUG_KMS("Adding cvt approximation of native panel mode %s\n", mode->name);
> }
> --
> 2.17.1
>