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From: Kees Cook <keescook@chromium.org>
Date: Sun, 10 Dec 2017 16:51:15 -0800
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Subject: Re: [PATCH] doc: convert printk-formats.txt to rst
To: Dan Carpenter <dan.carpenter@oracle.com>,
        Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joe Perches <joe@perches.com>, "Tobin C. Harding" <me@tobin.cc>,
        Dan Carpenter <error27@gmail.com>, Laura Abbott <labbott@redhat.com>,
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On Sat, Dec 9, 2017 at 3:48 AM, Dan Carpenter <dan.carpenter@oracle.com> wrote:
> On Fri, Dec 08, 2017 at 06:18:45PM -0800, Joe Perches wrote:
>> On Sat, 2017-12-09 at 12:27 +1100, Tobin C. Harding wrote:
>> > On Fri, Dec 08, 2017 at 01:22:37PM -0800, Joe Perches wrote:
>>
>> > > Outside of the documentation, what could be useful is for
>> > > someone to add a tool to verify %p<foo> extension to
>> > > the typeof address actually passed as an argument.
>> >
>> > This sounds interesting to work no. At first glance I have no idea how
>> > one would go about this. Some form of static analysis would be a good
>> > place to start, right? I'd like to allocate some cycles to this, any
>> > pointers most appreciated.
>>
>> A gcc-plugin would likely work best.
>>
>> There was some discussion about such a thing here:
>> http://www.openwall.com/lists/kernel-hardening/2017/02/14/38
>>
>> I vaguely recall someone else doing a broader use tool
>> which I believe was not smatch, but my google-fu isn't
>> finding it.
>
> Yeah.  Smatch has a check for this.  Rasmus Villemoes wrote it.

There's been some other work on format strings by Rasmus too. Thread
is here, which I still haven't caught back up on:

http://www.openwall.com/lists/kernel-hardening/2017/11/08/25

-Kees

-- 
Kees Cook
Pixel Security