2023-10-11 01:22:24

by Ma Ke

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

In radeon_tv_get_modes(), the return value of drm_cvt_mode()
is assigned to mode, which will lead to a NULL pointer
dereference on failure of drm_cvt_mode(). Add a check to
avoid null point dereference.

Signed-off-by: Ma Ke <[email protected]>
---
drivers/gpu/drm/radeon/radeon_connectors.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index d2f02c3dfce2..b84b58926106 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -1119,6 +1119,8 @@ static int radeon_tv_get_modes(struct drm_connector *connector)
else {
/* only 800x600 is supported right now on pre-avivo chips */
tv_mode = drm_cvt_mode(dev, 800, 600, 60, false, false, false);
+ if (!tv_mode)
+ return 0;
tv_mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
drm_mode_probed_add(connector, tv_mode);
}
--
2.37.2

2023-10-12 16:26:54

by Alex Deucher

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

On Tue, Oct 10, 2023 at 9:32 PM Ma Ke <[email protected]> wrote:
>
> In radeon_tv_get_modes(), the return value of drm_cvt_mode()
> is assigned to mode, which will lead to a NULL pointer
> dereference on failure of drm_cvt_mode(). Add a check to
> avoid null point dereference.
>
> Signed-off-by: Ma Ke <[email protected]>

Applied. Thanks!

Alex

> ---
> drivers/gpu/drm/radeon/radeon_connectors.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
> index d2f02c3dfce2..b84b58926106 100644
> --- a/drivers/gpu/drm/radeon/radeon_connectors.c
> +++ b/drivers/gpu/drm/radeon/radeon_connectors.c
> @@ -1119,6 +1119,8 @@ static int radeon_tv_get_modes(struct drm_connector *connector)
> else {
> /* only 800x600 is supported right now on pre-avivo chips */
> tv_mode = drm_cvt_mode(dev, 800, 600, 60, false, false, false);
> + if (!tv_mode)
> + return 0;
> tv_mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> drm_mode_probed_add(connector, tv_mode);
> }
> --
> 2.37.2
>