From mboxrd@z Thu Jan  1 00:00:00 1970
From: Lee Jones <lee.jones@linaro.org>
Subject: Re: [RESEND v4 2/6] remoteproc: debugfs: Add ability to boot remote
 processor using debugfs
Date: Tue, 12 Jan 2016 10:53:19 +0000
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To: Bjorn Andersson <bjorn@kryo.se>
Cc: Arnd Bergmann <arnd@arndb.de>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, Ohad Ben-Cohen <ohad@wizery.com>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, Florian Fainelli <f.fainelli@gmail.com>, kernel@stlinux.com, Nathan Lynch <Nathan_Lynch@mentor.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, ludovic.barre@st.com, Maxime Coquelin <maxime.coquelin@st.com>
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On Mon, 28 Dec 2015, Bjorn Andersson wrote:

> On Fri, Dec 4, 2015 at 12:24 AM, Lee Jones <lee.jones@linaro.org> wro=
te:
> > On Thu, 03 Dec 2015, Arnd Bergmann wrote:
> >
> >> On Thursday 03 December 2015 17:28:30 Lee Jones wrote:
> >> > >
> >> > > Ah, interesting. I haven't tried myself, and just tried to rea=
d the
> >> > > code. Maybe glibc already catches zero-length writes before it=
 gets
> >> > > into the kernel, or I just missed the part of the syscall that=
 checks
> >> > > for this.
> >> >
> >> > Glibc is responsible indeed:
> >> >
> >> >   http://osxr.org/glibc/source/io/write.c
> >>
> >> Ok, so an attacker can force the stack overflow by calling
> >> syscall(__NR_write, fd, p, 0) if that has any potential value,
> >> but normal users won't hit this case.
> >
> > Right.  I have fixed the issue (and another one I found) anyway, if
> > only to rid the GCC warning.
> >
>=20
> Sorry, but I'm unable to find a new version of this patch, did I miss
> it or could you resend it?

I didn't send it out.  Just looking at this again, post-vacation.

> Also, as I looked at this again, we should probably return an error i=
f
> count >=3D sizeof(buf) rather than just acknowledging the input (same=
 in
> the other debugfs write function in this file).

Sure.

--=20
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org =E2=94=82 Open source software for ARM SoCs
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