Message-ID: <bfd1801c-9d1e-0574-a237-711d3d5ae755@xs4all.nl>
Date:   Thu, 9 Dec 2021 12:58:45 +0100
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Subject: Re: [PATCH] media: meson: vdec: potential dereference of null pointer
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To:     Jiasheng Jiang <jiasheng@iscas.ac.cn>, narmstrong@baylibre.com,
        mchehab@kernel.org, gregkh@linuxfoundation.org,
        khilman@baylibre.com, jbrunet@baylibre.com,
        martin.blumenstingl@googlemail.com
Cc:     linux-media@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-staging@lists.linux.dev,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20211209085840.2081024-1-jiasheng@iscas.ac.cn>
From:   Hans Verkuil <hverkuil@xs4all.nl>
In-Reply-To: <20211209085840.2081024-1-jiasheng@iscas.ac.cn>
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On 09/12/2021 09:58, Jiasheng Jiang wrote:
> he return value of kzalloc() needs to be checked.
> To avoid use of null pointer in case of the failure of alloc.
> 
> Fixes: 876f123b8956 ("media: meson: vdec: bring up to compliance")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> ---
>  drivers/staging/media/meson/vdec/vdec_helpers.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/staging/media/meson/vdec/vdec_helpers.c b/drivers/staging/media/meson/vdec/vdec_helpers.c
> index 7f07a9175815..025885fcfec6 100644
> --- a/drivers/staging/media/meson/vdec/vdec_helpers.c
> +++ b/drivers/staging/media/meson/vdec/vdec_helpers.c
> @@ -234,6 +234,8 @@ void amvdec_add_ts(struct amvdec_session *sess, u64 ts,
>  	unsigned long flags;
>  
>  	new_ts = kzalloc(sizeof(*new_ts), GFP_KERNEL);
> +	if (!new_ts)
> +		return;

While this avoids dereferencing a NULL pointer, this error isn't propagated to the
caller. And I'm not sure if that's right.

Neil, what should be done in this case?

Regards,

	Hans

>  	new_ts->ts = ts;
>  	new_ts->tc = tc;
>  	new_ts->offset = offset;
>