Re: [PATCH] spi: pxa2xx: Add missed security checks

From: Chuhong Yuan <hslester96@gmail.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Daniel Mack <daniel@zonque.org>,
	Haojian Zhuang <haojian.zhuang@gmail.com>,
	Robert Jarzmik <robert.jarzmik@free.fr>,
	Mark Brown <broonie@kernel.org>,
	linux-arm Mailing List <linux-arm-kernel@lists.infradead.org>,
	linux-spi <linux-spi@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] spi: pxa2xx: Add missed security checks
Date: Mon, 28 Oct 2019 09:38:00 +0800	[thread overview]
Message-ID: <CANhBUQ2WJaFrk5JBDbTjaTM5mv0ebwdcHBoR8ODm28X_mOukLA@mail.gmail.com> (raw)
In-Reply-To: <CAHp75Vdb19w02zKHo1tqAtF8TmT=z6Ye2YFfxVw_TGtO3VxfLA@mail.gmail.com>

On Fri, Oct 18, 2019 at 10:04 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
>
> On Fri, Oct 18, 2019 at 2:37 PM Chuhong Yuan <hslester96@gmail.com> wrote:
> > On Fri, Oct 18, 2019 at 7:14 PM Andy Shevchenko
> > <andy.shevchenko@gmail.com> wrote:
> > > On Fri, Oct 18, 2019 at 1:39 PM Chuhong Yuan <hslester96@gmail.com> wrote:
> > > > On Fri, Oct 18, 2019 at 5:35 PM Andy Shevchenko
> > > > <andy.shevchenko@gmail.com> wrote:
> > > > > On Fri, Oct 18, 2019 at 8:59 AM Chuhong Yuan <hslester96@gmail.com> wrote:
>
> > > > > I'm not sure they are mandatory for all platforms.
> > > > > To be on the safe side, you simple need to add _optional() to the both
> > > > > call along with above change.
> > > > >
> > > >
> > > > As I know, this is the only one in spi which does not have a check for
> > > > devm_clk_get.
> > >
> > > For some it still may be optional. That's why better to check it and
> > > mention in the commit message.
> > >
> > > > Even if add _optional(), they still may return errors and need security checks.
> > >
> > > Of course, see "along with" in my previous comment.
> > >
> >
> > Got it. I will send version 2 in which both _optional() and security
> > checks will be added.
>
> Let me be clear. I didn't check if _optional() needed or not. You need
> to investigate this before sending new verison.
> And in either case this should be explained in commit message.
>

I have checked this file again and found ssp->clk is used by clk_get_rate in
pxa2xx_spi_probe.
Therefore, it should not be NULL and _optional cannot be used here.
Besides, ssp->irq is also used in pxa2xx_spi_probe.
Hence, I think this patch is fine.

Regards,
Chuhong

> --
> With Best Regards,
> Andy Shevchenko