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Date: Fri, 26 Jul 2024 09:48:57 +0200
From: Greg KH <gregkh@linuxfoundation.org>
To: Chen Ni <nichen@iscas.ac.cn>
Cc: laurent.pinchart@ideasonboard.com, mchehab@kernel.org,
	sakari.ailus@linux.intel.com, hverkuil-cisco@xs4all.nl,
	linux-media@vger.kernel.org, linux-staging@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] staging: media: omap4iss: add check for
 media_pad_remote_pad_first
Message-ID: <2024072625-stubborn-garlic-11ae@gregkh>
References: <20240726072814.3534601-1-nichen@iscas.ac.cn>
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In-Reply-To: <20240726072814.3534601-1-nichen@iscas.ac.cn>

On Fri, Jul 26, 2024 at 03:28:14PM +0800, Chen Ni wrote:
> Add check for the return value of media_pad_remote_pad_first() and
> return the error if it fails in order to avoid NULL pointer dereference.
> 
> Fixes: b2e44430b634 ("media: mc-entity: Rename media_entity_remote_pad() to media_pad_remote_pad_first()")
> Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
> ---
>  drivers/staging/media/omap4iss/iss_csi2.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/staging/media/omap4iss/iss_csi2.c b/drivers/staging/media/omap4iss/iss_csi2.c
> index 0e6c5bd81930..43851bbd0cc3 100644
> --- a/drivers/staging/media/omap4iss/iss_csi2.c
> +++ b/drivers/staging/media/omap4iss/iss_csi2.c
> @@ -539,6 +539,9 @@ static int csi2_configure(struct iss_csi2_device *csi2)
>  		return -EBUSY;
>  
>  	pad = media_pad_remote_pad_first(&csi2->pads[CSI2_PAD_SINK]);
> +	if (!pad)
> +		return -EPIPE;

How was this found and tested?

thanks,

greg k-h