From: Arnd Bergmann <arnd@arndb.de>
To: linux-arm-kernel@lists.infradead.org
Cc: Lee Jones <lee.jones@linaro.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@mentor.com,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Bjorn Andersson <bjorn@kryo.se>, ludovic.barre@st.com,
        Maxime Coquelin <maxime.coquelin@st.com>
Subject: Re: [RESEND v4 2/6] remoteproc: debugfs: Add ability to boot remote processor using debugfs
Date: Thu, 03 Dec 2015 22:12:59 +0100
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On Thursday 03 December 2015 17:28:30 Lee Jones wrote:
> > 
> > Ah, interesting. I haven't tried myself, and just tried to read 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.

	Arnd
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