2023-10-07 03:25:08

by Ma Ke

Subject: [PATCH] drm/nouveau/dispnv04: fix a possible null pointer dereference

In nv17_tv_get_ld_modes(), 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.

Signed-off-by: Ma Ke <[email protected]>
---
drivers/gpu/drm/nouveau/dispnv04/tvnv17.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
index 670c9739e5e1..4a08e61f3336 100644
--- a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
+++ b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
@@ -209,6 +209,8 @@ static int nv17_tv_get_ld_modes(struct drm_encoder *encoder,
struct drm_display_mode *mode;

mode = drm_mode_duplicate(encoder->dev, tv_mode);
+ if (!mode)
+ continue;

mode->clock = tv_norm->tv_enc_mode.vrefresh *
mode->htotal / 1000 *
--
2.37.2

2023-10-12 17:59:12

by Danilo Krummrich

Subject: Re: [PATCH] drm/nouveau/dispnv04: fix a possible null pointer dereference

On 10/7/23 05:23, Ma Ke wrote:
> In nv17_tv_get_ld_modes(), 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.
>
> Signed-off-by: Ma Ke <[email protected]>

Reviewed-by: Danilo Krummrich <[email protected]>

> ---
> drivers/gpu/drm/nouveau/dispnv04/tvnv17.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
> index 670c9739e5e1..4a08e61f3336 100644
> --- a/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
> +++ b/drivers/gpu/drm/nouveau/dispnv04/tvnv17.c
> @@ -209,6 +209,8 @@ static int nv17_tv_get_ld_modes(struct drm_encoder *encoder,
> struct drm_display_mode *mode;
>
> mode = drm_mode_duplicate(encoder->dev, tv_mode);
> + if (!mode)
> + continue;
>
> mode->clock = tv_norm->tv_enc_mode.vrefresh *
> mode->htotal / 1000 *