From: David Safford <safford@watson.ibm.com>
To: James Morris <jmorris@namei.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>, Shaz <shazalive@gmail.com>,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
Dave Hansen <dave@linux.vnet.ibm.com>,
Arjan van de Ven <arjan@infradead.org>,
securityengineeringresearchgroup
<securityengineeringresearchgroup@googlegroups.com>
Subject: Re: [ProbableSpam] Re: [PATCH 00/14] EVM
Date: Fri, 04 Jun 2010 16:25:55 -0400 [thread overview]
Message-ID: <1275683155.2644.91.camel@localhost.localdomain> (raw)
In-Reply-To: <alpine.LRH.2.00.1006041052450.1003@tundra.namei.org>
On Fri, 2010-06-04 at 10:57 +1000, James Morris wrote:
> On Tue, 1 Jun 2010, Mimi Zohar wrote:
>
> > SELinux, Smack, Capabilities, and IMA all use extended attributes. The
> > purpose of EVM is to detect offline tampering of these security extended
> > attributes.
>
> One issue mentioned to me off-list is that if EVM is only protecting
> against offline attacks, why not just encrypt the entire volume ?
>
> This would provide confidentiality and integrity protection for all data
> and metadata, rather than just integrity for xattr metadata.
Software whole disk encryption is slower, and doesn't really provide
integrity protection. While there are encryption modes, such as
IAPM (Integrity Aware Parallelizable Mode) which can provide both
confidentially and integrity guarantees, they are hard to use for
random access devices. An example attack is replaying previously
valid encrypted blocks, to revert to a previous version with a known
vulnerabiity. With EVM, these attacks can be defeated
efficiently with directory level binding. (This is on our TODO list).
With encryption in the hard disk, the performance is less of an issue,
but the integrity problem is still there. Plus, most systems don't
have the encrypting drives, and need a software solution.
dave
prev parent reply other threads:[~2010-06-04 20:26 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-21 21:49 [PATCH 00/14] EVM Mimi Zohar
2010-04-21 21:49 ` [PATCH 01/14] integrity: move ima inode integrity data management Mimi Zohar
2010-04-21 21:49 ` [PATCH 02/14] security: move LSM xattrnames to xattr.h Mimi Zohar
2010-04-21 21:49 ` [PATCH 03/14] xattr: define vfs_getxattr_alloc and vfs_xattr_cmp Mimi Zohar
2010-04-26 18:50 ` Serge E. Hallyn
2010-04-21 21:49 ` [PATCH 04/14] evm: re-release Mimi Zohar
2010-04-26 21:03 ` Serge E. Hallyn
2010-06-04 14:28 ` Stephen Smalley
2010-06-04 14:53 ` Mimi Zohar
2010-06-04 15:20 ` Stephen Smalley
2010-06-04 18:08 ` David Safford
2010-04-21 21:49 ` [PATCH 05/14] ima: move ima_file_free before releasing the file Mimi Zohar
2010-04-21 21:49 ` [PATCH 06/14] security: imbed evm calls in security hooks Mimi Zohar
2010-04-21 21:49 ` [PATCH 07/14] evm: inode post removexattr Mimi Zohar
2010-04-21 21:49 ` [PATCH 08/14] evm: imbed evm_inode_post_setattr Mimi Zohar
2010-04-21 21:49 ` [PATCH 09/14] evm: inode_post_init Mimi Zohar
2010-04-21 21:49 ` [PATCH 10/14] fs: add evm_inode_post_init calls Mimi Zohar
2010-04-21 21:49 ` [PATCH 11/14] ima: integrity appraisal extension Mimi Zohar
2010-04-21 21:49 ` [PATCH 12/14] ima: appraise default rules Mimi Zohar
2010-04-21 21:49 ` [PATCH 13/14] ima: inode post_setattr Mimi Zohar
2010-04-21 21:49 ` [PATCH 14/14] ima: add ima_inode_setxattr and ima_inode_removexattr Mimi Zohar
2010-04-21 21:58 ` [PATCH 00/14] EVM Randy Dunlap
2010-04-21 22:18 ` Mimi Zohar
2010-04-21 22:23 ` Randy Dunlap
2010-04-21 22:41 ` Mimi Zohar
2010-05-31 0:20 ` James Morris
2010-05-31 10:02 ` Shaz
2010-05-31 10:08 ` Shaz
2010-06-01 19:28 ` Mimi Zohar
2010-06-02 7:03 ` Dmitry Kasatkin
2010-06-02 7:50 ` Shaz
2010-06-02 9:12 ` Dmitry Kasatkin
2010-06-02 10:15 ` Shaz
2010-06-02 10:23 ` Dmitry Kasatkin
2010-06-02 14:02 ` Mimi Zohar
2010-06-04 6:53 ` Shaz
2010-06-04 15:09 ` Mimi Zohar
2010-06-04 18:47 ` Shaz
2010-06-04 0:57 ` James Morris
2010-06-04 6:56 ` Shaz
2010-06-04 20:25 ` David Safford [this message]
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