Date: Fri, 11 Nov 2016 10:56:02 +0000
From: Liviu Dudau <liviu.dudau@arm.com>
To: Shailendra Verma <shailendra.v@samsung.com>
Cc: Brian Starkey <brian.starkey@arm.com>,
        Mali DP Maintainers <malidp@foss.arm.com>,
        David Airlie <airlied@linux.ie>, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org,
        Shailendra Verma <shailendra.capricorn@gmail.com>,
        vidushi.koul@samsung.com
Subject: Re: [PATCH] Gpu: drm: arm: - Fix possible dereference of NULL
Message-ID: <20161111105601.GJ10219@e106497-lin.cambridge.arm.com>
References: <1478853968-25169-1-git-send-email-shailendra.v@samsung.com>
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Hi Shailendra,

On Fri, Nov 11, 2016 at 02:16:08PM +0530, Shailendra Verma wrote:
> From: "Shailendra Verma" <shailendra.v@samsung.com>
> 
> There is possible dereference of NULL pointer if kmalloc fails.

You could add: ... when the function returns. From the patch itself it is
not clear where the problem is.

> So return NULL if kmalloc fails.
> 
> Signed-off-by: Shailendra Verma <Shailendra.v@samsung.com>

Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>

Thanks for spotting this!
Liviu

> ---
>  drivers/gpu/drm/arm/malidp_planes.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/arm/malidp_planes.c b/drivers/gpu/drm/arm/malidp_planes.c
> index 82c193e..f769398 100644
> --- a/drivers/gpu/drm/arm/malidp_planes.c
> +++ b/drivers/gpu/drm/arm/malidp_planes.c
> @@ -54,6 +54,9 @@ struct drm_plane_state *malidp_duplicate_plane_state(struct drm_plane *plane)
>  		return NULL;
>  
>  	state = kmalloc(sizeof(*state), GFP_KERNEL);
> +	if (!state)
> +		return NULL;
> +
>  	if (state) {
>  		m_state = to_malidp_plane_state(plane->state);
>  		__drm_atomic_helper_plane_duplicate_state(plane, &state->base);
> -- 
> 1.7.9.5
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯