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From: zohar@linux.vnet.ibm.com (Mimi Zohar)
To: linux-security-module@vger.kernel.org
Subject: [RFC PATCH 3/3] fs: detect that the i_rwsem has already been taken exclusively
Date: Mon, 02 Oct 2017 08:25:09 -0400	[thread overview]
Message-ID: <1506947109.5691.282.camel@linux.vnet.ibm.com> (raw)
In-Reply-To: <87zi9ai63l.fsf@xmission.com>

On Sun, 2017-10-01 at 22:25 -0500, Eric W. Biederman wrote:
> Mimi Zohar <zohar@linux.vnet.ibm.com> writes:

> > There should be no open writers in ima_check_last_writer(), so the
> > file shouldn't be changing.
> 
> This is slightly tangential but I think important to consider.
> What do you do about distributed filesystems fuse, nfs, etc that
> can change the data behind the kernels back.

Exactly!

> Do you not support such systems or do you have a sufficient way to
> detect changes?

Currently, only the initial file access in policy is measured,
verified, audited. ?Even if there was a way of detecting the change,
since we can't trust these file systems, the performance would be
awful, but we should probably not be caching the
measurement/verification results.

Mimi

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  reply	other threads:[~2017-10-02 12:25 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-28 12:39 [RFC PATCH 0/3] define new read_iter file operation rwf flag Mimi Zohar
2017-09-28 12:39 ` [RFC PATCH 1/3] fs: define new read_iter " Mimi Zohar
2017-09-28 13:54   ` Matthew Wilcox
2017-09-28 14:33     ` Mimi Zohar
2017-09-28 15:51     ` Linus Torvalds
2017-09-28 12:39 ` [RFC PATCH 2/3] integrity: use call_read_iter to calculate the file hash Mimi Zohar
2017-09-28 12:39 ` [RFC PATCH 3/3] fs: detect that the i_rwsem has already been taken exclusively Mimi Zohar
2017-09-28 22:02   ` Dave Chinner
2017-09-28 23:39     ` Linus Torvalds
2017-09-29  0:12       ` Mimi Zohar
2017-09-29  0:33         ` Linus Torvalds
2017-09-29  1:53           ` Mimi Zohar
2017-09-29  3:26             ` Linus Torvalds
2017-10-01  1:33               ` Eric W. Biederman
     [not found]                 ` <CA+55aFx726wT4VprN-sHm6s8Q_PV_VjhTBC4goEbMcerYU1Tig@mail.gmail.com>
2017-10-01 12:08                   ` Mimi Zohar
2017-10-01 18:41                     ` Linus Torvalds
2017-10-01 22:34                       ` Dave Chinner
2017-10-01 23:15                         ` Linus Torvalds
2017-10-02  3:54                           ` Dave Chinner
2017-10-01 23:42                         ` Mimi Zohar
2017-10-02  3:25                           ` Eric W. Biederman
2017-10-02 12:25                             ` Mimi Zohar [this message]
2017-10-02  4:35                           ` Dave Chinner
2017-10-02 12:09                             ` Mimi Zohar
2017-10-02 12:43                               ` Jeff Layton
2017-10-01 22:06                   ` Eric W. Biederman
2017-10-01 22:20                     ` Linus Torvalds
2017-10-01 23:54                       ` Mimi Zohar

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