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

[Gustavo A. R. Silva]

Hello,

On 11/21/2017 02:22 AM, Patrice CHOTARD wrote:
> 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@xxxxxxxxxxxxxx>
> > ---
> >    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@xxxxxx>
>
> Thanks

Thank you, Patrice.

--
Gustavo A. R. Silva