Re: [PATCH] drm/komeda: return early if drm_universal_plane_init() fails.

From: Steven Price <steven.price@arm.com>
To: Liviu Dudau <liviu.dudau@arm.com>
Cc: "James \(Qian\) Wang" <james.qian.wang@arm.com>,
	dri-devel <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH] drm/komeda: return early if drm_universal_plane_init() fails.
Date: Fri, 3 Dec 2021 10:25:16 +0000	[thread overview]
Message-ID: <15e178b3-a181-ebd6-a372-f621c8e9d2d2@arm.com> (raw)
In-Reply-To: <20211203100946.2706922-1-liviu.dudau@arm.com>

On 03/12/2021 10:09, Liviu Dudau wrote:
> If drm_universal_plane_init() fails early we jump to the common cleanup code
> that calls komeda_plane_destroy() which in turn could access the uninitalised
> drm_plane and crash. Return early if an error is detected without going through
> the common code.
> 
> Reported-by: Steven Price <steven.price@arm.com>
> Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>

Reviewed-by: Steven Price <steven.price@arm.com>

Looks correct, although I note there is a path in
__drm_universal_plane_init() which doesn't clean up properly. I'll send
a patch for that too.

Thanks,

Steve

> ---
>  drivers/gpu/drm/arm/display/komeda/komeda_plane.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c
> index aa193c58f4bf6d9..517b94c3bcaf966 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_plane.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_plane.c
> @@ -279,8 +279,10 @@ static int komeda_plane_add(struct komeda_kms_dev *kms,
>  
>  	komeda_put_fourcc_list(formats);
>  
> -	if (err)
> -		goto cleanup;
> +	if (err) {
> +		kfree(kplane);
> +		return err;
> +	}
>  
>  	drm_plane_helper_add(plane, &komeda_plane_helper_funcs);
>  
> 