Re: Memory leaks in bash-4.4.0

[Bruce Dubbs]

Chet Ramey wrote:
> On 1/29/17 6:48 PM, Bruce Dubbs wrote:
>
> > Bash Version: 4.4
> > Patch Level: 0
> > Release Status: release
> >
> > Description:
> >
> >     When running regression tests on libinput, I get two different leaks
> > identified by valgrind. The files below are not a part of libinput but are
> > a part of bash.
>
> What is libinput?

https://www.freedesktop.org/software/libinput/

> >     ==10733== 11 bytes in 1 blocks are definitely lost in loss record 81 of 290
> >     ==10733==    at 0x4C2AACD: malloc (vg_replace_malloc.c:299)
> >     ==10733==    by 0x46F7BD: xmalloc (xmalloc.c:112)
> >     ==10733==    by 0x469598: set_default_locale (locale.c:81)
> >     ==10733==    by 0x419950: main (shell.c:411)
> >     ==10733==
>
> http://lists.gnu.org/archive/html/bug-bash/2015-07/msg00073.html
>
> >     ==10733== 17 bytes in 1 blocks are definitely lost in loss record 112 of
> > 290
> >     ==10733==    at 0x4C2AACD: malloc (vg_replace_malloc.c:299)
> >     ==10733==    by 0x46F7BD: xmalloc (xmalloc.c:112)
> >     ==10733==    by 0x4524EA: make_dev_fd_filename (subst.c:5692)
> >     ==10733==    by 0x4524EA: process_substitute (subst.c:5751)
> >     ==10733==    by 0x4524EA: expand_word_internal (subst.c:9172)
> >     ==10733==    by 0x454E33: shell_expand_word_list (subst.c:10565)
> >     ==10733==    by 0x454E33: expand_word_list_internal (subst.c:10688)
> >     ==10733==    by 0x42F14E: execute_simple_command (execute_cmd.c:4153)
> >     ==10733==    by 0x43134B: execute_command_internal (execute_cmd.c:802)
> >     ==10733==    by 0x432BDD: execute_command (execute_cmd.c:405)
> >     ==10733==    by 0x41BD51: reader_loop (eval.c:180)
> >     ==10733==    by 0x41AAAA: main (shell.c:792)
>
> It would help if there were a short reproducer for this, so I can verify
> it.

I'll see what I can do.

> > I was not able to trace everything through, but xmalloc.c:112 does:
> >
> >    temp = malloc (bytes);
> >
> > and as best I can tell, temp is never freed.
>
> xmalloc is a malloc wrapper, and `temp' is the return value from the
> function.

Yes, I know.  The issue is that the caller, in this case 
set_default_locale or possibly main, never runs free on the allocated 
space.  I tried to trace it in set_default_locale but there are a lot of 
paths and I didn't follow it all.  I'll look some more and get back to you.

  -- Bruce