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From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Joe Perches <joe@perches.com>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	stable <stable@vger.kernel.org>, Andy Lavr <andy.lavr@gmail.com>,
	Arvind Sankar <nivedita@alum.mit.edu>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Sami Tolvanen <samitolvanen@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Alexandru Ardelean <alexandru.ardelean@analog.com>,
	Yury Norov <yury.norov@gmail.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] lib/string.c: implement stpcpy
Date: Fri, 28 Aug 2020 11:17:39 +0300	[thread overview]
Message-ID: <CAHp75VcGOvYOXCaQeux5PQ+tHRYF3W=173s80U=mDE-0zzwTXg@mail.gmail.com> (raw)
In-Reply-To: <202008271523.88796F201F@keescook>

On Fri, Aug 28, 2020 at 1:26 AM Kees Cook <keescook@chromium.org> wrote:
>
> On Thu, Aug 27, 2020 at 11:05:42PM +0300, Andy Shevchenko wrote:
> > In general it's better to have a robust API, but what may go wrong
> > with the interface where we have no length of  the buffer passed, but
> > we all know that it's PAGE_SIZE?
> > So, what's wrong with doing something like
> > strcpy(buf, "Yes, we know we won't overflow here\n");
>
> (There's a whole thread[1] about this right now, actually.)
>
> The problem isn't the uses where it's safe (obviously), it's about the
> uses where it is NOT safe. (Or _looks_ safe but isn't.) In order to
> eliminate bug classes, we need remove the APIs that are foot-guns. Even
> if one developer never gets it wrong, others might.
>
> [1] https://lore.kernel.org/lkml/c256eba42a564c01a8e470320475d46f@AcuMS.aculab.com/T/#mac95487d7ae427de03251b49b75dd4de40c2462d

Seems to me that this is a fixation on an abstract problem that never
exists (of course, if a developer has brains to think).

-- 
With Best Regards,
Andy Shevchenko

  reply	other threads:[~2020-08-28  8:18 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-25 13:58 [PATCH v3] lib/string.c: implement stpcpy Nick Desaulniers
2020-08-25 18:51 ` Nathan Chancellor
2020-08-26 15:41 ` Sedat Dilek
2020-08-26 15:58 ` Masahiro Yamada
2020-09-06  9:57   ` Kees Cook
2020-08-26 16:49 ` Masahiro Yamada
2020-08-26 16:57   ` Joe Perches
2020-08-26 16:58     ` Nick Desaulniers
2020-08-26 22:59       ` Masahiro Yamada
2020-08-26 23:38         ` Kees Cook
2020-08-26 23:57           ` Joe Perches
2020-08-27  2:33             ` Kees Cook
2020-08-27  2:42               ` Joe Perches
2020-08-27 18:26                 ` Kees Cook
2020-08-27  8:59           ` Andy Shevchenko
2020-08-27 18:30             ` Kees Cook
2020-08-27 19:37               ` Joe Perches
2020-08-27 19:41                 ` Kees Cook
2020-08-27 20:05               ` Andy Shevchenko
2020-08-27 22:26                 ` Kees Cook
2020-08-28  8:17                   ` Andy Shevchenko [this message]
2020-08-31 23:21                     ` Nick Desaulniers
2020-09-01  8:51                       ` David Laight
2020-08-25 14:00 Nick Desaulniers
2020-08-26 15:22 ` Kees Cook

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