Re: [PATCH] media: meson: vdec: potential dereference of null pointer

[Hans Verkuil]

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@xxxxxxxxxxx>
> ---
>  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;
>