On Tue, Sep 15, 2020 at 04:36:08PM +0100, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> Currently the LIRC_GET_MIN_TIMEOUT is checking for a null dev->max_timeout
> and then accessing dev->min_timeout, hence we may have a potential null
> pointer dereference issue. This looks like a cut-n-paste typo, fix it
> by checking on dev->min_timeout before accessing it.
max_timeout and min_timeout are both u32, not pointers. So, the commit
message is wrong: there is no null pointer dereference issue.
Every driver which has max_timeout also has min_timeout set (I've checked
for this). So technically this is not wrong, but maybe it looks wrong?
Thanks,
Sean
>
> Addresses-Coverity: ("Copy-paste error")
> Fixes: e589333f346b ("V4L/DVB: IR: extend interfaces to support more device settings")
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> drivers/media/rc/lirc_dev.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
> index 220363b9a868..d230c21e1d31 100644
> --- a/drivers/media/rc/lirc_dev.c
> +++ b/drivers/media/rc/lirc_dev.c
> @@ -533,7 +533,7 @@ static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>
> /* Generic timeout support */
> case LIRC_GET_MIN_TIMEOUT:
> - if (!dev->max_timeout)
> + if (!dev->min_timeout)
> ret = -ENOTTY;
> else
> val = dev->min_timeout;
> --
> 2.27.0
On 15/09/2020 18:12, Sean Young wrote:
> On Tue, Sep 15, 2020 at 04:36:08PM +0100, Colin King wrote:
>> From: Colin Ian King <[email protected]>
>>
>> Currently the LIRC_GET_MIN_TIMEOUT is checking for a null dev->max_timeout
>> and then accessing dev->min_timeout, hence we may have a potential null
>> pointer dereference issue. This looks like a cut-n-paste typo, fix it
>> by checking on dev->min_timeout before accessing it.
>
> max_timeout and min_timeout are both u32, not pointers. So, the commit
> message is wrong: there is no null pointer dereference issue.
>
> Every driver which has max_timeout also has min_timeout set (I've checked
> for this). So technically this is not wrong, but maybe it looks wrong?
Oops. I totally misread the analysis report. My bad.
>
> Thanks,
>
> Sean
>>
>> Addresses-Coverity: ("Copy-paste error")
>> Fixes: e589333f346b ("V4L/DVB: IR: extend interfaces to support more device settings")
>> Signed-off-by: Colin Ian King <[email protected]>
>> ---
>> drivers/media/rc/lirc_dev.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c
>> index 220363b9a868..d230c21e1d31 100644
>> --- a/drivers/media/rc/lirc_dev.c
>> +++ b/drivers/media/rc/lirc_dev.c
>> @@ -533,7 +533,7 @@ static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>>
>> /* Generic timeout support */
>> case LIRC_GET_MIN_TIMEOUT:
>> - if (!dev->max_timeout)
>> + if (!dev->min_timeout)
>> ret = -ENOTTY;
>> else
>> val = dev->min_timeout;
>> --
>> 2.27.0