[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <6cb75b56-b1b4-d381-1110-1e0cad5fb6b4@flausch.at>
Date: Sat, 15 Apr 2017 12:13:28 +0200
From: Andreas Lausch-Waas <andreas@...usch.at>
To: oss-security@...ts.openwall.com
Subject: Re: alloca in inline functions can be dangerous
On 2017-04-10 16:55, Leandro Pereira wrote:
> On Mon, Apr 10, 2017 at 7:36 AM, Jason A. Donenfeld <Jason@...c4.com> wrote:
>> I'm interested if anybody else has encountered this behavior or has any
>> thoughts about it.
> Yes, and I usually mark those functions with __attribute__((noinline))
> to avoid precisely this kind of behavior.
>
This (VLAs in loops or inlines filling the stack) would be a gcc bug:
"Jumping or breaking out of the scope of the array name deallocates the
storage. Jumping into the scope is not allowed; you get an error message
for it.". See https://gcc.gnu.org/onlinedocs/gcc/Variable-Length.html
At least GCC 6.3.1 does not call alloca for VLAs.
--
Andreas
Powered by blists - more mailing lists
Please check out the
Open Source Software Security Wiki, which is counterpart to this
mailing list.
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
