From: Dan Carpenter <dan.carpenter@oracle.com>
To: Andi Kleen <ak@linux.intel.com>
Cc: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>,
Grant Likely <grant.likely@linaro.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lib: string.c: Added a funktion function strzcpy
Date: Wed, 24 Sep 2014 18:41:42 +0300 [thread overview]
Message-ID: <20140924154142.GG5865@mwanda> (raw)
In-Reply-To: <20140924143555.GJ28253@tassilo.jf.intel.com>
On Wed, Sep 24, 2014 at 07:35:55AM -0700, Andi Kleen wrote:
> On Wed, Sep 24, 2014 at 10:52:06AM +0300, Dan Carpenter wrote:
> > On Tue, Sep 23, 2014 at 06:17:53PM -0700, Andi Kleen wrote:
> > > On Wed, Sep 24, 2014 at 12:13:36AM +0200, Rickard Strandqvist wrote:
> > > > Added a function strzcpy which works the same as strncpy,
> > > > but guaranteed to produce the trailing null character.
> > >
> > > Do we really need the bizarre strncpy padding semantics for anything?
> > > Why not just use strlcpy?
> >
> > We do need the padding in many places to prevent information leaks.
>
> Like where?
>
You're asking what would break if we switched every strncpy() to
strlcpy() but it's not an easy question to answer.
I've looked a lot at information leaks, but strings are still a blind
spot for my Smatch. My check only looks at normal variables, arrays.
Eventually I hope to fix this, of course.
I did a git search and Rickard has added some examples, but there were
definitely other places that rely strncpy() padding before.
regards,
dan carpenter
next prev parent reply other threads:[~2014-09-24 15:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-23 22:13 [PATCH] lib: string.c: Added a funktion function strzcpy Rickard Strandqvist
2014-09-23 22:13 ` Rickard Strandqvist
2014-09-23 22:40 ` Andrew Morton
2014-09-24 1:17 ` Andi Kleen
2014-09-24 7:52 ` Dan Carpenter
2014-09-24 14:14 ` Lennart Sorensen
2014-09-24 14:35 ` Andi Kleen
[not found] ` <CAFo99gZUfFUB9xX0GYW=hJMNouiU-M9apZ8KtPg9MW3x7gxZcg@mail.gmail.com>
2014-09-24 14:58 ` Andi Kleen
2014-09-24 15:41 ` Dan Carpenter [this message]
2014-09-24 20:51 ` Rickard Strandqvist
2014-09-24 21:26 ` Andrew Morton
2014-09-24 21:49 ` Rickard Strandqvist
2014-09-24 22:55 ` Andi Kleen
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