Re: [RFA] Fix memory corruption bug in mdebugread.c

[Michael Snyder <msnyder@redhat.com>]

Fred Fish wrote:
> 
> The code to handle stabs continuation in mdebugread.c incorrectly
> attempts to overwrite memory returned by realloc with the original
> contents of the memory passed to realloc.  This is wrong for two
> reasons; first realloc will do any copying needed if the string is
> moved, and second, the copy at the old location may be corrupted by
> the time realloc returns a pointer to the new location.
> 
> This patch fixes the problem.
> 
> -Fred

Looks correct to me.  Since the file has no maintainer, 
I'll give approval.  

> 2002-01-23  Fred Fish  <fnf@redhat.com>
> 
>         * mdebugread.c (parse_partial_symbols): Only copy stabstring1 to
>         stabstring on initial malloc.  Reallocing will copy it for us,
>         if necessary.
> 
> Index: mdebugread.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/mdebugread.c,v
> retrieving revision 1.22
> diff -c -p -r1.22 mdebugread.c
> *** mdebugread.c        2002/01/20 19:42:04     1.22
> --- mdebugread.c        2002/01/24 00:02:24
> *************** parse_partial_symbols (struct objfile *o
> *** 2707,2714 ****
>                      && stabstring != debug_info->ss + fh->issBase + sh.iss)
>                       stabstring = xrealloc (stabstring, len + len2 + 1);
>                     else
> !                     stabstring = xmalloc (len + len2 + 1);
> !                   strcpy (stabstring, stabstring1);
>                     strcpy (stabstring + len, stabstring2);
>                     len += len2;
>                   }
> --- 2707,2716 ----
>                      && stabstring != debug_info->ss + fh->issBase + sh.iss)
>                       stabstring = xrealloc (stabstring, len + len2 + 1);
>                     else
> !                     {
> !                       stabstring = xmalloc (len + len2 + 1);
> !                       strcpy (stabstring, stabstring1);
> !                     }
>                     strcpy (stabstring + len, stabstring2);
>                     len += len2;
>                   }