From: Matthew Wilcox <matthew@wil.cx>
To: Thibaut VARENE <varenet@parisc-linux.org>
Cc: Roel Kluin <roel.kluin@gmail.com>,
kyle@mcmartin.ca, deller@gmx.de, linux-parisc@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] kobject: Read buffer overflow
Date: Sun, 2 Aug 2009 04:16:36 -0600 [thread overview]
Message-ID: <20090802101635.GA3711@parisc-linux.org> (raw)
In-Reply-To: <7d01f9f00908020306s273eec60u8e50692c0f839828@mail.gmail.com>
On Sun, Aug 02, 2009 at 12:06:59PM +0200, Thibaut VARENE wrote:
> On Sun, Aug 2, 2009 at 10:02 AM, Roel Kluin<roel.kluin@gmail.com> wrote:
> > Check whether index is within bounds before testing the element.
>
> The change is correct but:
> - There are other places in the code with that construct. Even though
> they wouldn't trigger an overflow, why not fixing them too?
> - Keep the likely: we are more likely to run out of data in the layers
> than to exhaust the counter (which is why no overflow was ever
> triggered, I believe ;-)
No, lose the likely. It's a for-loop; gcc will do the right thing.
(If you think I'm wrong, convince me by showing the disassembly of the
compiled code with and without the likely).
--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
next prev parent reply other threads:[~2009-08-02 10:16 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-02 8:02 [PATCH] kobject: Read buffer overflow Roel Kluin
2009-08-02 10:06 ` Thibaut VARENE
2009-08-02 10:16 ` Matthew Wilcox [this message]
2009-08-02 10:24 ` Thibaut VARENE
2009-08-02 23:33 ` James Bottomley
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