Re: gm4 format strings on OSX

[Peter Pentchev]

On Mon, Oct 22, 2001 at 04:32:23AM +0300, Peter Pentchev wrote:
> On Sat, Oct 20, 2001 at 12:22:31PM -0700, address@hidden wrote:
[snip]
> > [OSXBOX:~] elguapo% gm4 %s
> > gm4: Memory bounds violation detected (SIGSEGV).  Either a stack overflow
> > occurred, or there is a bug in gm4.  Check for possible infinite 
> > recursion.
> > Segmentation fault
> 
> [CC'd to bug-gnu-utils, hopefully this is the right address; if it is
>  not (GNU seems to have moved away from prep.ai), then please somebody
>  notify the current m4 maintainers]
> 
> Confirmed with GNU m4 1.4 on FreeBSD 4.4-STABLE as of Oct 21.
> 
> The attached patch fixes the reported segfault and one other unsafe
> use of the m4 internal function error().  I have not looked at other
> functions within m4 that might use printf(3) and friends unsafely,
> so there might be other bugs lurking about.

For the record, I just committed that patch to the FreeBSD port
of GNU m4.  Therefore, the devel/m4 FreeBSD port at version m4-1.4_1
as of Mon Oct 22 02:03:10 2001 UTC is not vulnerable at least to
this particular format string attack.

And just as a side note, it seems I was wrong about GNU having moved
away from prep.ai.mit.edu.  ftp.gnu.org/gnuftp.gnu.org are just
aliases.  Should have known better than to speak before checking :)

G'luck,
Peter

-- 
What would this sentence be like if pi were 3?