linux-kernel - Re: [RFC] ipc: introduce shm_rmid

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 for Android: free password hash cracker in your pocket

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

Date:	Fri, 1 Jul 2011 14:04:53 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Vasiliy Kulikov <segoon@...nwall.com>
Cc:	solar@...nwall.com, Andrew Morton <akpm@...ux-foundation.org>,
	kernel-hardening@...ts.openwall.com,
	Randy Dunlap <rdunlap@...otime.net>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	"Serge E. Hallyn" <serge.hallyn@...onical.com>,
	Daniel Lezcano <daniel.lezcano@...e.fr>,
	Oleg Nesterov <oleg@...hat.com>, Tejun Heo <tj@...nel.org>,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-security-module@...r.kernel.org
Subject: Re: [RFC] ipc: introduce shm_rmid_forced sysctl


* Vasiliy Kulikov <segoon@...nwall.com> wrote:

> On Fri, Jul 01, 2011 at 13:25 +0200, Ingo Molnar wrote:
> > Furthermore, if testing shows that this is not actually breaking 
> > anything in a serious way we could also in theory simplify the patch 
> > and just make this the default behavior with no runtime ability to 
> > switch it off.
> 
> I'm afraid it's impossible.  From -ow readme:
> 
> "Of course, this breaks the way things are defined, so some 
> applications might stop working. In particular, expect most 
> commercial databases to break. Apache and PostgreSQL are known to 
> work, though. :-)"
> 
> http://www.openwall.com/linux/README.shtml
> 
> But as it was written in days of Linux 2.4.x, the situation could 
> have changed.  A desktop system seems to work.

As we really prefer working systems over non-working ones (and lots 
of unattached shm segments can clearly result in a non-working 
system) we can only accept the "this will break stuff" argument if 
it's *demonstrated* to break stuff and if the failure scenario is 
carefully described in the commit.

It would take a serious breakage to override a "system locks up 
swapping itself to death" failure scenario.

Thanks,

	Ingo
--
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/