From: Tejun Heo <tj@kernel.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>,
Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org
Subject: Re: PING^7 (was Re: [PATCH v2 00/14] Corrections and customization of the SG_IO command whitelist (CVE-2012-4542))
Date: Thu, 23 May 2013 09:54:31 +0900 [thread overview]
Message-ID: <20130523005431.GA17291@mtj.dyndns.org> (raw)
In-Reply-To: <20130522221737.GA12339@mtj.dyndns.org>
On Thu, May 23, 2013 at 07:17:37AM +0900, Tejun Heo wrote:
> > No, it doesn't. You can use SCM_RIGHTS, and pass a file descriptor for
> > the device node to an unprivileged program. You can choose the
> > users/groups that are allowed to access the device. In either case, the
> > privileged action is limited in time or in scope.
> >
> > The count-me-out knob affects all processes that use the device node,
> > and won't be cleaned up properly if you SIGKILL the (privileged)
> > process that sets it. So if you can avoid it, you should.
>
> Then let's make it fit the use case better. I really can't see much
> point in crafting the cdb filter when you basically have to entrust
> the device to the user anyway. Let's either trust the user with the
One more thing, is it really necessary to have finer granularity than
provided by file permissions? What would be the use case? Do you
expect to have multiple - two - differing levels of access with and
without SG_IO? Note that, for the same user, it's pointless to give
out SG_IO access to processes while denying for other processes. As
long as ptrace can be attached, hijacking such fd is easy. Making it
per-device should be suitable enough, no?
--
tejun
next prev parent reply other threads:[~2013-05-23 0:54 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-06 15:15 [PATCH v2 00/14] Corrections and customization of the SG_IO command whitelist (CVE-2012-4542) Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 01/14] sg_io: pass request_queue to blk_verify_command Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 02/14] sg_io: reorganize list of allowed commands Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 03/14] sg_io: use different default filters for each device class Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 04/14] sg_io: resolve conflicts between commands assigned to multiple classes (CVE-2012-4542) Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 05/14] sg_io: whitelist a few more commands for rare & obsolete device types Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 06/14] sg_io: whitelist another command for multimedia devices Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 07/14] sg_io: whitelist a few more commands for media changers Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 08/14] sg_io: whitelist a few more commands for tapes Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 09/14] sg_io: whitelist a few more commands for disks Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 10/14] sg_io: whitelist a few obsolete commands Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 11/14] sg_io: mark blk_set_cmd_filter_defaults as __init Paolo Bonzini
2013-02-06 15:15 ` [PATCH v2 12/14] sg_io: remove remnants of sysfs SG_IO filters Paolo Bonzini
2013-02-06 15:16 ` [PATCH v2 13/14] sg_io: introduce unpriv_sgio queue flag Paolo Bonzini
2013-02-06 15:16 ` [PATCH v2 14/14] sg_io: use unpriv_sgio to disable whitelisting for scanners Paolo Bonzini
2013-02-13 8:32 ` [PATCH v2 00/14] Corrections and customization of the SG_IO command whitelist (CVE-2012-4542) Paolo Bonzini
2013-02-13 15:35 ` Douglas Gilbert
2013-02-13 15:48 ` Paolo Bonzini
2013-02-20 16:12 ` Paolo Bonzini
2013-03-22 22:30 ` PING^2 " Paolo Bonzini
2013-04-04 18:18 ` PING^3 " Paolo Bonzini
2013-04-17 12:26 ` PING^4 aka The Jon Corbet Effect " Paolo Bonzini
2013-04-27 13:31 ` PING^5 aka New ways to attract attentions " Paolo Bonzini
2013-05-06 20:43 ` PING^6 " Paolo Bonzini
2013-05-22 6:35 ` PING^7 (was Re: [PATCH v2 00/14] Corrections and customization of the SG_IO command whitelist (CVE-2012-4542)) Paolo Bonzini
2013-05-22 9:32 ` Tejun Heo
2013-05-22 9:53 ` Paolo Bonzini
2013-05-22 10:02 ` Tejun Heo
2013-05-22 10:23 ` Paolo Bonzini
2013-05-22 12:07 ` James Bottomley
2013-05-22 14:07 ` Paolo Bonzini
2013-05-22 16:31 ` Paolo Bonzini
2013-05-22 13:41 ` Tejun Heo
2013-05-22 14:12 ` Paolo Bonzini
2013-05-22 14:30 ` Tejun Heo
2013-05-22 15:00 ` Paolo Bonzini
2013-05-22 19:30 ` Tejun Heo
2013-05-22 21:18 ` Paolo Bonzini
2013-05-22 22:17 ` Tejun Heo
2013-05-23 0:54 ` Tejun Heo [this message]
2013-05-23 7:45 ` Paolo Bonzini
2013-05-23 9:02 ` Tejun Heo
2013-05-23 9:47 ` Paolo Bonzini
2013-05-24 1:44 ` Tejun Heo
2013-05-24 7:13 ` Paolo Bonzini
2013-05-24 8:02 ` Tejun Heo
2013-05-24 8:31 ` Paolo Bonzini
2013-05-24 9:07 ` Tejun Heo
2013-05-24 9:45 ` Paolo Bonzini
2013-05-24 22:20 ` Tejun Heo
2013-05-25 4:35 ` James Bottomley
2013-05-25 5:27 ` Christoph Hellwig
2013-05-25 7:05 ` Paolo Bonzini
2013-05-25 7:11 ` Christoph Hellwig
2013-05-25 7:21 ` Paolo Bonzini
2013-06-21 11:57 ` Christoph Hellwig
2013-05-25 8:37 ` Tejun Heo
2013-05-25 11:14 ` Paolo Bonzini
2013-05-25 12:48 ` Tejun Heo
2013-05-25 12:56 ` Paolo Bonzini
2013-05-22 15:03 ` Theodore Ts'o
2013-05-22 15:53 ` Paolo Bonzini
2013-05-22 16:32 ` Martin K. Petersen
2013-05-22 17:00 ` Paolo Bonzini
2013-05-22 18:11 ` Theodore Ts'o
2013-05-22 19:37 ` Paolo Bonzini
2013-05-22 20:19 ` Theodore Ts'o
2013-05-22 20:36 ` Paolo Bonzini
2013-05-25 3:54 ` Vladislav Bolkhovitin
2013-05-28 20:25 ` Martin K. Petersen
2013-05-29 6:12 ` Vladislav Bolkhovitin
2013-05-22 20:39 ` Tejun Heo
2013-05-22 21:12 ` Paolo Bonzini
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