From: "Serge E. Hallyn" <serue@us.ibm.com>
To: Kyle Moffett <mrmacman_g4@mac.com>
Cc: Andreas Gruenbacher <agruen@suse.de>,
James Morris <jmorris@namei.org>,
Chris Wright <chrisw@sous-sol.org>,
linux-security-module@vger.kernel.org,
"Serge E. Hallyn" <serue@us.ibm.com>,
Andrew Morgan <agm@google.com>, Andrew Morton <akpm@google.com>,
Stephen Smalley <sds@tycho.nsa.gov>,
lkml <linux-kernel@vger.kernel.org>,
Arjan van de Ven <arjan@infradead.org>, Greg KH <greg@kroah.com>,
Eric Paris <eparis@redhat.com>
Subject: Re: [PATCH try #2] security: Convert LSM into a static interface
Date: Tue, 26 Jun 2007 08:47:12 -0500 [thread overview]
Message-ID: <20070626134712.GA8615@sergelap.austin.ibm.com> (raw)
In-Reply-To: <11C35822-4E11-4365-BADE-C1AE41F15B50@mac.com>
Quoting Kyle Moffett (mrmacman_g4@mac.com):
> On Jun 25, 2007, at 16:37:58, Andreas Gruenbacher wrote:
> >On Monday 25 June 2007 06:33, James Morris wrote:
> >>Convert LSM into a static interface, as the ability to unload a
> >>security module is not required by in-tree users and potentially
> >>complicates the overall security architecture.
> >
> >It's useful for some LSMs to be modular, and LSMs which are y/n
> >options won't have any security architecture issues with unloading
> >at all. The mere fact that SELinux cannot be built as a module is a
> >rather weak argument for disabling LSM modules as a whole, so
> >please don't.
>
> Here are a few questions for you:
>
> 1) What do you expect to happen to all the megs of security data
> when you "rmmod selinux"?
Read the sentence right above yours again.
Noone is saying we should be able to rmmod selinux.
> Do you maintain a massive linked list of
> security data (with all the locking and performance problems) so that
> you can iterate over it calling kfree()? What synchronization
> primitive do we have right now which could safely stop all CPUs
> outside of security calls while we NULL out and free security data
> and disable security operations? Don't say "software suspend" and
> "process freezer", since those have whole order-of-magnitude-
> complexity problems of their own (and don't always work right either).
>
> 2) When you "modprobe my_custom_security_module", how exactly do
> you expect that all the processes, files, shared memory segments,
> file descriptors, sockets, SYSV mutexes, packets, etc will get
> appropriate security pointers?>
Those don't all need labels for capabilities, for instance. This
question is as wrong as the last one.
> This isn't even solvable the same way
> the "rmmod" problem is, since most of that isn't even accessible
> without iterating over the ENTIRE dcache, icache, every process,
> every process' file-descriptors, every socket, every unix socket,
> every anonymous socket, every SYSV shm object, every currently-in-
> process packet.
>
> 3) This sounds suspiciously like "The mere fact that the
> Linux-2.6-VM cannot be built as a module is a rather weak argument
> for disabling VFS modules as a whole". We don't do "pluggable
No, your argument sounds like "my fs can't be a module so neither should
any."
> fundamental infrastructure" in Linux. If it's fundamental
> infrastructure then you eliminate as many differences as possible and
> leave the rest to CONFIG options (or delete it entirely).
>
>
> So... Do you have a proposal for solving those rather fundamental
> design gotchas? If so, I'm sure everybody here would love to see
> your patch; though maybe not if it's a 32MB patch-zilla-of-doom (AKPM
> beware, the merge-conflict-from-hell is on its way). On the other
> hand, if you accept that these problems basically can't be solved and
> we make things static and rip out a bunch of code, we can probably
> improve our performance under larger security models (like SELinux/
> AppArmor/TOMOYO/MagicSecurityFlavorOfTheWeek(TM)) by a percent or two.
>
> Cheers,
> Kyle Moffett
>
> -
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next prev parent reply other threads:[~2007-06-26 13:47 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20070611123714.GA2063@sergelap.austin.ibm.com>
[not found] ` <878322.98602.qm@web36606.mail.mud.yahoo.com>
[not found] ` <afff21250706110926l244ddc28i44289cb08a6721e2@mail.gmail.com>
[not found] ` <20070617135239.GA17689@sergelap>
[not found] ` <4676007F.7060503@kernel.org>
[not found] ` <20070618044017.GW3723@sequoia.sous-sol.org>
[not found] ` <20070620171037.GA28670@sergelap.ibm.com>
[not found] ` <20070620174613.GF3723@sequoia.sous-sol.org>
2007-06-21 16:00 ` implement-file-posix-capabilities.patch Serge E. Hallyn
2007-06-23 8:13 ` implement-file-posix-capabilities.patch Andrew Morgan
2007-06-24 15:51 ` implement-file-posix-capabilities.patch Serge E. Hallyn
2007-06-24 16:18 ` implement-file-posix-capabilities.patch James Morris
2007-06-24 20:58 ` [PATCH][RFC] security: Convert LSM into a static interface James Morris
2007-06-24 22:09 ` Chris Wright
2007-06-24 22:37 ` James Morris
2007-06-25 1:38 ` Chris Wright
2007-06-24 23:40 ` Casey Schaufler
2007-06-25 1:39 ` Chris Wright
2007-06-25 3:37 ` Casey Schaufler
2007-06-25 3:57 ` Chris Wright
2007-06-25 13:02 ` Casey Schaufler
2007-06-25 14:24 ` Roberto De Ioris
2007-06-25 4:33 ` [PATCH try #2] " James Morris
2007-06-25 4:48 ` Petr Vandrovec
2007-06-25 4:58 ` James Morris
2007-06-25 16:59 ` Stephen Smalley
2007-06-25 23:56 ` [PATCH try #3] " James Morris
2007-06-25 20:37 ` [PATCH try #2] " Andreas Gruenbacher
2007-06-25 21:14 ` James Morris
2007-06-26 3:57 ` Serge E. Hallyn
2007-06-26 13:15 ` Adrian Bunk
2007-06-26 14:06 ` Serge E. Hallyn
2007-06-26 14:59 ` Adrian Bunk
2007-06-26 15:53 ` Serge E. Hallyn
2007-06-26 18:52 ` Adrian Bunk
2007-06-26 18:18 ` Greg KH
2007-06-26 18:40 ` Serge E. Hallyn
2007-06-26 4:09 ` Kyle Moffett
2007-06-26 4:25 ` Kyle Moffett
2007-06-26 13:47 ` Serge E. Hallyn [this message]
2007-06-27 0:07 ` Kyle Moffett
2007-06-27 0:57 ` Crispin Cowan
2007-06-27 1:22 ` Kyle Moffett
2007-06-27 4:24 ` Chris Wright
2007-06-27 13:41 ` Serge E. Hallyn
2007-06-27 14:36 ` James Morris
2007-06-27 17:21 ` Serge E. Hallyn
2007-06-27 18:51 ` Serge E. Hallyn
2007-06-27 19:28 ` James Morris
2007-06-28 2:48 ` Serge E. Hallyn
2007-06-25 3:57 ` [PATCH][RFC] " Serge E. Hallyn
2007-06-25 4:10 ` Chris Wright
2007-06-25 4:54 ` Serge E. Hallyn
2007-06-25 13:50 ` Casey Schaufler
2007-06-25 13:54 ` James Morris
2007-06-25 14:32 ` Serge E. Hallyn
2007-06-25 15:08 ` Casey Schaufler
2007-06-27 5:00 ` implement-file-posix-capabilities.patch Andrew Morgan
2007-06-27 13:16 ` implement-file-posix-capabilities.patch Serge E. Hallyn
2007-06-28 6:19 ` implement-file-posix-capabilities.patch Andrew Morgan
2007-06-28 13:36 ` implement-file-posix-capabilities.patch Serge E. Hallyn
2007-06-28 15:14 ` implement-file-posix-capabilities.patch Casey Schaufler
2007-06-28 15:38 ` implement-file-posix-capabilities.patch Serge E. Hallyn
2007-06-28 15:56 ` implement-file-posix-capabilities.patch Casey Schaufler
2007-06-29 5:30 ` implement-file-posix-capabilities.patch Andrew Morgan
2007-06-29 13:24 ` implement-file-posix-capabilities.patch Serge E. Hallyn
2007-06-29 14:46 ` implement-file-posix-capabilities.patch Casey Schaufler
2007-06-28 15:50 ` implement-file-posix-capabilities.patch Andrew Morgan
2007-07-02 14:38 ` implement-file-posix-capabilities.patch Serge E. Hallyn
2007-07-04 21:29 ` implement-file-posix-capabilities.patch Andrew Morgan
2007-07-04 23:00 ` implement-file-posix-capabilities.patch Casey Schaufler
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