linux-kernel - Re: [PATCH] proc: Add complete process group list

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 22 Jun 2010 15:37:57 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Mike McCormack <mikem@...g3k.org>
Cc:	oleg@...hat.com, kosaki.motohiro@...fujitsu.com, serue@...ibm.com,
	jmorris@...ei.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] proc: Add complete process group list

On Wed, 23 Jun 2010 00:07:26 +0900
Mike McCormack <mikem@...g3k.org> wrote:

> If a process is in more than NGROUPS_SMALL (32) groups, it's not possible
>  for any other user space process to determine the list of groups it is
>  in using /proc/<pid>/status.
> 
> Increasing the list of groups listed by /proc/<pid>/status would lead to
>  very long lines that file, and possible misbehavior of userspace programs
>  that parse /proc/<pid>/status, so instead I have opted to create a new
>  file /proc/<pid>/groups, which contains the list of supplementary groups
>  for each pid.
> 
> The new file /proc/<pid>/groups consists of a single group id per line,
>  with each line being 11 characters long.  This should be enough space
>  for 16bit or 32bit group ids.
> 
> This feature might be useful for a server listening on a unix domain pipe
>  to determine the list of groups that a client process is in from its pid.

"might be"?

It would be useful to hear a bit more about usage scenarios, why this
is needed, etc - some hard info which would justify permanent extension
of the kernel->userspace API.  How does this get used, why is it
needed, what are the alternatives, etc.

I don't recall having heard of anyone using the groups fields in
/proc/pid/status before.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/