Re: Bug in GNU Awk 3.1.5

[Karel Zak]

On Wed, Jan 03, 2007 at 12:07:02PM +0100, Jürgen Kahrs wrote:
> Filip Gieszczykiewicz wrote:
> 
> > Triggered by:
> > ls /usr/lib/* | grep -v "/" | awk '{if (length($1) > 14) {print $1}}'
> 
> Thanks for boiling the problem down to a one-liner.

 Yes, thanks!
 
> > Get dump:
> > *** glibc detected *** awk: double free or corruption (fasttop):
> > 0x083b78f8 ***
> > ======= Backtrace: =========
> > /lib/libc.so.6[0x890efd]
> > /lib/libc.so.6(cfree+0x90)[0x894550]
> 
> This problem can indeed be reproduced with GNU Awk
> 3.1.5 as supplied since August 2005 at
> 
>   http://ftp.gnu.org/gnu/gawk/gawk-3.1.5.tar.gz
> 
> > Stock Fedora Core 6:
> > Linux localhost.localdomain 2.6.18-1.2798.fc6 #1 SMP Mon Oct 16 14:54:20
> > EDT 2006 i686 athlon i386
> > GNU/Linux

 I'm going to release gawk FC update today.

> This problem does _not_ appear after applying the patches
> to 3.1.5 that Arnold posted here.

 Well, it's patch:

     Date: Mon, 18 Dec 2006 18:22:57 +0300
     From: "Dmitry V. Levin" <address@hidden>
     Subject: gawk: invalid free in str2wstr()

 This patch and also the second Levin's patch (that fixes
 zeroizing in free_wstr()) are not in gawk-stable tree yet.

> > I plead ignorance to knowing how to debug stuff in a pipe with gdb.

 Hehe.. I usually add "sleep(n)" to the main() and attache by gdb to
 pid of the sleeping process.

    Karel

-- 
 Karel Zak  <address@hidden>