Re: [PATCH] c8sectpfe: fix potential NULL pointer dereference in c8sectpfe_timer_interrupt

[Patrice CHOTARD <patrice.chotard@st.com>]

Hi Gustavo

On 11/20/2017 03:00 PM, Gustavo A. R. Silva wrote:
> _channel_ is being dereferenced before it is null checked, hence there is a
> potential null pointer dereference. Fix this by moving the pointer dereference
> after _channel_ has been null checked.
> 
> This issue was detected with the help of Coccinelle.
> 
> Fixes: c5f5d0f99794 ("[media] c8sectpfe: STiH407/10 Linux DVB demux support")
> Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
> ---
>   drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c b/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c
> index 59280ac..23d0ced 100644
> --- a/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c
> +++ b/drivers/media/platform/sti/c8sectpfe/c8sectpfe-core.c
> @@ -83,7 +83,7 @@ static void c8sectpfe_timer_interrupt(unsigned long ac8sectpfei)
>   static void channel_swdemux_tsklet(unsigned long data)
>   {
>   	struct channel_info *channel = (struct channel_info *)data;
> -	struct c8sectpfei *fei = channel->fei;
> +	struct c8sectpfei *fei;
>   	unsigned long wp, rp;
>   	int pos, num_packets, n, size;
>   	u8 *buf;
> @@ -91,6 +91,8 @@ static void channel_swdemux_tsklet(unsigned long data)
>   	if (unlikely(!channel || !channel->irec))
>   		return;
>   
> +	fei = channel->fei;
> +
>   	wp = readl(channel->irec + DMA_PRDS_BUSWP_TP(0));
>   	rp = readl(channel->irec + DMA_PRDS_BUSRP_TP(0));
>   
> 

Acked-by: Patrice Chotard <patrice.chotard@st.com>

Thanks