2023-10-13 02:01:41

by Ma Ke

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

In amdgpu_vkms_conn_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 pointer
dereference.

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

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
index 7148a216ae2f..db6fc0cb18eb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
@@ -239,6 +239,8 @@ static int amdgpu_vkms_conn_get_modes(struct drm_connector *connector)

for (i = 0; i < ARRAY_SIZE(common_modes); i++) {
mode = drm_cvt_mode(dev, common_modes[i].w, common_modes[i].h, 60, false, false, false);
+ if (!mode)
+ continue;
drm_mode_probed_add(connector, mode);
}

--
2.37.2

2023-10-13 13:43:31

by Alex Deucher

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

On Thu, Oct 12, 2023 at 10:32 PM Ma Ke <[email protected]> wrote:
>
> In amdgpu_vkms_conn_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 pointer
> dereference.
>
> Signed-off-by: Ma Ke <[email protected]>

Applied. Thanks!

Alex

> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
> index 7148a216ae2f..db6fc0cb18eb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vkms.c
> @@ -239,6 +239,8 @@ static int amdgpu_vkms_conn_get_modes(struct drm_connector *connector)
>
> for (i = 0; i < ARRAY_SIZE(common_modes); i++) {
> mode = drm_cvt_mode(dev, common_modes[i].w, common_modes[i].h, 60, false, false, false);
> + if (!mode)
> + continue;
> drm_mode_probed_add(connector, mode);
> }
>
> --
> 2.37.2
>