Date: Fri, 28 Dec 2007 20:20:20 -0600 (CST) From: Mike Silbersack <silby@silby.com> To: Gunther Mayer <gunther.mayer@googlemail.com> Cc: freebsd-security@freebsd.org Subject: Re: ProPolice/SSP in 7.0 Message-ID: <20071228200428.J6052@odysseus.silby.com> In-Reply-To: <4774EB0F.90103@googlemail.com> References: <477277FF.30504@googlemail.com> <86myrvhht9.fsf@ds4.des.no> <20071227195833.154b41ae@kan.dnsalias.net> <4774EB0F.90103@googlemail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 28 Dec 2007, Gunther Mayer wrote:
> Btw, I second the motion of having SSP enabled by default in FreeBSD, other
> OS's have been doing this for years at a negligible performance overhead.
>
> Gunther
It's too late to make that sort of change for FreeBSD 7.0, but I think
that's a good goal for FreeBSD 8.0.
Here's what I think you could do:
1. Verify that enabling SSP works properly.
2. Convince Kris Kennaway to run his mysql benchmarks on a FreeBSD 8
system both with and without SSP to verify that there is no significant
slowdown.
3. Get it enabled on FreeBSD 8 by default.
4. Request that the change be made to FreeBSD 7.1 or 7.2 after it has
proven to not cause problems on FreeBSD 8.
Since the subject came up, I just tried using it, and it's not giving me
the results I expected. Take the following program:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void overrun(void);
int main(void)
{
overrun();
}
void overrun(void)
{
int x;
char a[4];
int y;
strcpy(a, "ABCDE");
printf("hi");
}
If I compile it like so:
> cc -g -fstack-protector-all overrun.c
The overrun is detected and the program is aborted.
> ./a.out
Abort (core dumped)
But if I compile it like so:
> cc -g -fstack-protector overrun.c
The overrun is not caught.
> ./a.out
hi>
Either I'm doing something wrong, or we have gcc misconfigured and it's
not detecting that strcpy is a function which needs to be watched
closedly.
Mike "Silby" Silbersack
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20071228200428.J6052>