2023-02-15 17:15:58

by Alexander Sapozhnikov

[permalink] [raw]

Subject: [PATCH] gpu-drm-tiny-cirrus: Add NULL check of pointer pipe->plane.state->fb in cirrus_pipe_update()

---

From: Alexandr Sapozhnikov <[email protected]>

After having been compared to NULL value at cirrus.c:455, pointer 'pipe->plane.state->fb' is passed as
1st parameter in call to function 'cirrus_fb_blit_rect' at cirrus.c:461, where it is dereferenced at cirrus.c:316.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Alexandr Sapozhnikov <[email protected]>
---
drivers/gpu/drm/tiny/cirrus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
index 678c2ef..ffa7e61 100644
--- a/drivers/gpu/drm/tiny/cirrus.c
+++ b/drivers/gpu/drm/tiny/cirrus.c
@@ -455,7 +455,7 @@ static void cirrus_pipe_update(struct drm_simple_display_pipe *pipe,
if (state->fb && cirrus->cpp != cirrus_cpp(state->fb))
cirrus_mode_set(cirrus, &crtc->mode, state->fb);

- if (drm_atomic_helper_damage_merged(old_state, state, &rect))
+ if (state->fb && drm_atomic_helper_damage_merged(old_state, state, &rect))
cirrus_fb_blit_rect(state->fb, &shadow_plane_state->data[0], &rect);
}

--
2.5.3

2023-02-17 10:14:30

by Thomas Zimmermann

[permalink] [raw]

Subject: Re: [PATCH] gpu-drm-tiny-cirrus: Add NULL check of pointer pipe->plane.state->fb in cirrus_pipe_update()

---

Hi

Am 15.02.23 um 18:15 schrieb Alexander Sapozhnikov:
> From: Alexandr Sapozhnikov <[email protected]>
>
> After having been compared to NULL value at cirrus.c:455, pointer 'pipe->plane.state->fb' is passed as
> 1st parameter in call to function 'cirrus_fb_blit_rect' at cirrus.c:461, where it is dereferenced at cirrus.c:316.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Alexandr Sapozhnikov <[email protected]>

Reviewed-by: Thomas Zimmermann <[email protected]>

I'll add you patch to drm-misc-fixes.

Best regards
Thomas

> ---
> drivers/gpu/drm/tiny/cirrus.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
> index 678c2ef..ffa7e61 100644
> --- a/drivers/gpu/drm/tiny/cirrus.c
> +++ b/drivers/gpu/drm/tiny/cirrus.c
> @@ -455,7 +455,7 @@ static void cirrus_pipe_update(struct drm_simple_display_pipe *pipe,
> if (state->fb && cirrus->cpp != cirrus_cpp(state->fb))
> cirrus_mode_set(cirrus, &crtc->mode, state->fb);
>
> - if (drm_atomic_helper_damage_merged(old_state, state, &rect))
> + if (state->fb && drm_atomic_helper_damage_merged(old_state, state, &rect))
> cirrus_fb_blit_rect(state->fb, &shadow_plane_state->data[0], &rect);
> }
>

--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev

---

Attachments:

OpenPGP_signature (840.00 B)
OpenPGP digital signature