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From: Mark Geisert <mark@maxrnd.com>
To: cygwin@cygwin.com
Subject: Re: mkshortcut (cygutils-1.4.14)  free error
Date: Mon, 26 Oct 2015 10:08:00 -0000	[thread overview]
Message-ID: <loom.20151026T044455-64@post.gmane.org> (raw)
In-Reply-To: <1445823930.241438.419951441.109BA262@webmail.messagingengine.com>

Anthony Heading writes:
> I see the cygutils package has been orphaned, perhaps explaining the
> lack of response to the below.  
> A related question then is that the vanilla mkshortcut built from the
> latest source package does not
> seem to perfectly match the behaviour of the binary.    Is there any way
> to review or reproduce how
> the binary package was built, or any other way to verify that the source
> and binaries do match?

Unfortunately I have no answers for your good questions above.  But...

> On Sat, Oct 17, 2015, at 10:30 PM, Anthony Heading wrote:
> > Seems free() is being called on an adjusted pointer,  causing general
> > misbehaviour.  A minimal patch below.

[...sorry for deletions within the patch; trying to satisfy gmane...]
> > -  char *buf_str, *tmp_str;
> > +  char *buf_str, *tmp_str, *base_str;
[...]
> >        buf_str = xstrndup (opts.target_arg, strlen(opts.target_arg));
> > +      base_str = buf_str;
> >        tmp_str = buf_str;

...if tmp_str is not modified after the above line, ...

> >        tmp = strlen (buf_str) - 1;
> >        while (strrchr (buf_str, '/') == (buf_str + tmp))
> >  <at>  <at>  -504,7 +505,7  <at>  <at> 
> >            buf_str++;
> >          }
> >        link_name = xstrndup (tmp_str, strlen (tmp_str));
> > -      free (buf_str);
> > +      free (base_str);

...then "free(tmp_str);" should solve the original issue without having to
define a new variable base_str.  I didn't look at the complete original
code, only the patch that you posted, but hopefully this points to a "more
minimal" fix if you agree it's solid.

..mark




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  reply	other threads:[~2015-10-26  3:57 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-18  2:30 Anthony Heading
2015-10-26 10:01 ` Anthony Heading
2015-10-26 10:08   ` Mark Geisert [this message]
2015-10-26 10:36     ` Corinna Vinschen
2015-10-27  5:29     ` Anthony Heading
2015-10-26 16:03   ` Ken Brown
2015-10-27  0:11     ` Mark Geisert
2015-10-27  8:46       ` Anthony Heading
2015-10-27  9:30         ` Mark Geisert
2015-10-28  4:49           ` Anthony Heading
2015-10-28  9:15             ` Mark Geisert
2015-10-28 13:05               ` Corinna Vinschen
2015-10-28 14:49                 ` Mark Geisert

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