Re: Need help in writing a ChangeLog

["Carlos O'Donell" <carlos at systemhalted dot org>]

On Fri, Nov 19, 2010 at 2:51 AM, Pavel Labushev <p.labushev@gmail.com> wrote:
> Hello.
>
> I want to send a patch to libc-alpha@ and I need to write a proper ChangeLog.

Thank you for posting to libc-help for assitance.

I am one of the moderators and I saw your message in the queue. One
thing I wanted to note was that your mailer is line breaking at 88
characters which is producing odd artifacts when others read your
email. You should either (a) provide no line breaks or (b) break at <
78 characters (excluding CRLF).

> This is my current draft:
>
> 2010-11-19 ?Pavel Labushev ?<p.labushev@gmail.com>
>
> ? ? ? ?* elf/dl-environ.c (_dl_env_sanitize): New function.
> ? ? ? ?* elf/dl-support.c (_dl_non_dynamic_init): If __libc_enable_secure
> ? ? ? ?is true, sanitize the environment of privileged process using the
> ? ? ? ?system whitelist or blacklist file containing environment variable
> ? ? ? ?names.

The description of the patch should be verbose, but the ChangeLog need not be.

This should be more terse for example "If __libc_enable_secure then
sanitize the environment."

> ? ? ? ?* elf/Makefile: add environ to dl-routines list.
> ? ? ? ?* elf/rtld.c (process_envvars): If __libc_enable_secure is true,
> ? ? ? ?sanitize the environment of privileged process using the system
> ? ? ? ?whitelist or blacklist file containing environment variable names.

This should also be more terse.

> ? ? ? ?* sysdeps/generic/ldsodefs.h: Add prototype for _dl_env_sanitize.
> ? ? ? ?* sysdeps/generic/unsecvars.h: Define PRIVENV_WHITELIST_FILE and
> ? ? ? ?PRIVENV_BLACKLIST_FILE.
>
> Could you give me some advise if I should add or change anything, please?
> (Note that there's no bugzilla entry associated with the patch.)

You will need to write up description of the patch:
* Who: Who is it for? What class of users.
* What: What does it do?
* Where: Which parts of glibc are changed, and how does that effect
runtime performance?
* Why: Why should it be fixed in glibc and not in the kernel?

In general you should follow all of the steps in:
http://sourceware.org/glibc/wiki/Contribution%20checklist

This is significant amount of code, therefore you also need an FSF
copyright assignment (mentioned in the checklist).

> The patch:
>
[patch snipped]

Have you considered that this could be done in the kernel before the
process even starts? As it stands, static programs that have not been
rebuilt with this patch are still vulnerable? If you fixed this in the
kernel, then it fixes even the old static programs.

One might argue that environment sanitation is part of the kernel
security services?

Cheers,
Carlos.