2017-12-05 17:27:21

by Gustavo A. R. Silva

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

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 <[email protected]>
>> ---
>> 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 <[email protected]>
>
> Thanks

Thank you, Patrice.

--
Gustavo A. R. Silva