From: Matthew Garrett <mjg59@google.com>
To: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: linux-integrity@vger.kernel.org,
Mikhail Kurinnoi <viewizard@viewizard.com>
Subject: Re: RFC: Make it practical to ship EVM signatures
Date: Mon, 9 Oct 2017 10:59:34 -0700 [thread overview]
Message-ID: <CACdnJuv8QSkVNWf7FY2-jakiO2sd8gh1oRTji4w3fvic54kfmA@mail.gmail.com> (raw)
In-Reply-To: <1507571511.3748.9.camel@linux.vnet.ibm.com>
On Mon, Oct 9, 2017 at 10:51 AM, Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
>> >> I'm not really clear on what attacks are prevented by using the inode
>> >> number. If I'm able to preserve all the other security metadata when
>> >> copying a file, I can just create a hardlink to the original instead
>> >> and have the same outcome.
>> >
>> > The issue is the ability of having different security metadata, not
>> > the same security metadata. (I need to refresh my memory as to hard
>> > links, and whether they can have different security metadata.)
>>
>> If the security metadata is different then copying another
>> security.evm will fail, surely?
>
> The assumption here is that security.ima exists and is included in the
> HMAC calculation. For files which are not included in the IMA policy,
> the only thing binding the file data and metadata is the i_ino and
> uuid.
Ok, that makes sense. But for cases where we do have security.ima, the
inode doesn't seem to provide additional security but does make
deployment more difficult. Does supporting this use case seem
reasonable?
next prev parent reply other threads:[~2017-10-09 17:59 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-27 22:16 RFC: Make it practical to ship EVM signatures Matthew Garrett
2017-09-27 22:16 ` [PATCH 1/6] IMA: Allow EVM validation on appraisal even without a symmetric key Matthew Garrett
2017-10-01 2:08 ` Mimi Zohar
2017-10-02 17:02 ` Matthew Garrett
2017-10-02 19:41 ` Mimi Zohar
2017-09-27 22:16 ` [PATCH 2/6] EVM: Add infrastructure for making EVM fields optional Matthew Garrett
2017-09-27 22:16 ` [PATCH 3/6] EVM: Allow userland to override the default EVM attributes Matthew Garrett
2017-09-27 22:16 ` [PATCH 4/6] EVM: Add an hmac_ng xattr format Matthew Garrett
2017-09-27 22:16 ` [PATCH 5/6] EVM: Write out HMAC xattrs in the new format Matthew Garrett
2017-09-27 22:16 ` [PATCH 6/6] EVM: Add a new digital signature format Matthew Garrett
2017-09-28 20:12 ` RFC: Make it practical to ship EVM signatures Mimi Zohar
2017-09-28 21:13 ` Matthew Garrett
2017-09-29 0:53 ` Mimi Zohar
2017-09-29 18:09 ` Matthew Garrett
2017-09-29 19:02 ` Mimi Zohar
2017-09-29 19:17 ` Matthew Garrett
2017-09-29 20:01 ` Mimi Zohar
2017-09-29 20:09 ` Matthew Garrett
2017-10-01 2:36 ` Mimi Zohar
2017-10-02 17:09 ` Matthew Garrett
2017-10-02 19:54 ` Mimi Zohar
[not found] ` <CACdnJutYw7Pgh-EwWuwp9Wz+5KzoreZVr+c6UV30zC__8FZSVA@mail.gmail.com>
[not found] ` <1506974574.5691.304.camel@linux.vnet.ibm.com>
2017-10-02 20:07 ` Matthew Garrett
2017-10-09 17:51 ` Mimi Zohar
2017-10-09 17:59 ` Matthew Garrett [this message]
2017-10-09 18:15 ` Mimi Zohar
2017-10-09 18:18 ` Matthew Garrett
2017-10-09 18:40 ` Mimi Zohar
[not found] ` <20171009232314.545de76a@totoro>
[not found] ` <1507583449.3748.46.camel@linux.vnet.ibm.com>
[not found] ` <20171010003326.6409ae23@totoro>
2017-10-09 21:40 ` Mimi Zohar
2017-10-09 23:10 ` Mikhail Kurinnoi
2017-10-10 19:07 ` Mimi Zohar
2017-10-12 23:09 ` Dmitry Kasatkin
2017-10-18 19:48 ` Dmitry Kasatkin
2017-10-18 20:30 ` Mimi Zohar
2017-10-18 20:37 ` Dmitry Kasatkin
2017-10-18 21:02 ` Mikhail Kurinnoi
2017-10-18 21:07 ` Mimi Zohar
2017-10-19 10:14 ` Dmitry Kasatkin
2017-10-19 11:43 ` Mimi Zohar
2017-10-19 17:08 ` Matthew Garrett
2017-10-19 18:38 ` Dmitry Kasatkin
2017-10-19 10:36 ` Dmitry Kasatkin
2017-10-19 11:45 ` Mimi Zohar
2017-10-02 14:53 ` Roberto Sassu
2017-10-02 8:55 ` Roberto Sassu
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