From: Len Baker <len.baker@gmx.com>
To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Andy Gross <agross@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Magnus Damm <magnus.damm@gmail.com>,
Santosh Shilimkar <ssantosh@kernel.org>,
Len Baker <len.baker@gmx.com>, Kees Cook <keescook@chromium.org>,
David Laight <David.Laight@ACULAB.COM>,
Robin Murphy <robin.murphy@arm.com>,
linux-hardening@vger.kernel.org, linux-arm-msm@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v4 2/3] drivers/soc/renesas: Prefer memcpy over strcpy
Date: Tue, 10 Aug 2021 17:59:53 +0200 [thread overview]
Message-ID: <20210810155953.GB2508@titan> (raw)
In-Reply-To: <c33adb9e-9604-3d89-5a5b-152eb03e5b54@wanadoo.fr>
Hi,
On Sun, Aug 08, 2021 at 07:06:30PM +0200, Christophe JAILLET wrote:
> Hi,
>
> Le 08/08/2021 à 17:35, Bernd Petrovitsch a écrit :
> > Hi all!
> >
> > On 08/08/2021 14:50, Len Baker wrote:
> > > strcpy() performs no bounds checking on the destination buffer. This
> > > could result in linear overflows beyond the end of the buffer, leading
> > > to all kinds of misbehaviors. So, use memcpy() as a safe replacement.
> > >
> > > This is a previous step in the path to remove the strcpy() function
> > > entirely from the kernel.
> > >
> > > Signed-off-by: Len Baker <len.baker@gmx.com>
> > > ---
> > > drivers/soc/renesas/r8a779a0-sysc.c | 6 ++++--
> > > drivers/soc/renesas/rcar-sysc.c | 6 ++++--
> > > 2 files changed, 8 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/soc/renesas/r8a779a0-sysc.c b/drivers/soc/renesas/r8a779a0-sysc.c
> > > index d464ffa1be33..7410b9fa9846 100644
> > > --- a/drivers/soc/renesas/r8a779a0-sysc.c
> > > +++ b/drivers/soc/renesas/r8a779a0-sysc.c
> > > @@ -404,19 +404,21 @@ static int __init r8a779a0_sysc_pd_init(void)
> > > for (i = 0; i < info->num_areas; i++) {
> > > const struct r8a779a0_sysc_area *area = &info->areas[i];
> > > struct r8a779a0_sysc_pd *pd;
> > > + size_t n;
> > >
> > > if (!area->name) {
> > > /* Skip NULLified area */
> > > continue;
> > > }
> > >
> > > - pd = kzalloc(sizeof(*pd) + strlen(area->name) + 1, GFP_KERNEL);
> > > + n = strlen(area->name) + 1;
> > > + pd = kzalloc(sizeof(*pd) + n, GFP_KERNEL);
> > Zeroing the allocated bytes is not needed since it's completly
> > overwritten with the strcpy()/memcpy().
>
> The strcpy()/memcpy() only overwrites the pd->name field, not the whole pd
> structure.
You are right.
> I think that it is needed to keep the kzalloc.
Yes, I think so. The kzalloc is needed to guarantee that the whole struct is
initialize (all the members are initialized with zeros).
Regards,
Len
>
> Just my 2c,
> CJ
>
> > > if (!pd) {
> > > error = -ENOMEM;
> > > goto out_put;
> > > }
> > >
> > > - strcpy(pd->name, area->name);
> > > + memcpy(pd->name, area->name, n);
> > > pd->genpd.name = pd->name;
> > > pd->pdr = area->pdr;
> > > pd->flags = area->flags;
> >
> > And similar for the second hunk.
> >
> > MfG,
> > Bernd
> >
>
next prev parent reply other threads:[~2021-08-10 16:00 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-08 12:50 [PATCH v4 0/3] drivers/soc: Remove all strcpy() uses Len Baker
2021-08-08 12:50 ` [PATCH v4 1/3] drivers/soc/qcom: Prefer strscpy over strcpy Len Baker
2021-08-08 12:50 ` [PATCH v4 2/3] drivers/soc/renesas: Prefer memcpy " Len Baker
2021-08-08 15:35 ` Bernd Petrovitsch
2021-08-08 17:06 ` Christophe JAILLET
2021-08-10 15:59 ` Len Baker [this message]
2021-08-11 9:38 ` Geert Uytterhoeven
2021-08-08 12:50 ` [PATCH v4 3/3] drivers/soc/ti: Prefer strscpy " Len Baker
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