From: Colin Ian King <colin.king@canonical.com>
To: Sean Young <sean@mess.org>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
Maxim Levitsky <maximlevitsky@gmail.com>,
linux-media@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] media: rc: fix check on dev->min_timeout for LIRC_GET_MIN_TIMEOUT ioctl
Date: Tue, 15 Sep 2020 17:14:42 +0000 [thread overview]
Message-ID: <dc1fed82-d0dd-9dd3-d33c-1225ea7b80c3@canonical.com> (raw)
In-Reply-To: <20200915171256.GA681@gofer.mess.org>
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 <colin.king@canonical.com>
>>
>> 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 <colin.king@canonical.com>
>> ---
>> 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
prev parent reply other threads:[~2020-09-15 17:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-15 15:36 [PATCH] media: rc: fix check on dev->min_timeout for LIRC_GET_MIN_TIMEOUT ioctl Colin King
2020-09-15 17:12 ` Sean Young
2020-09-15 17:14 ` Colin Ian King [this message]
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