From: Mimi Zohar <zohar@linux.ibm.com>
To: linux-integrity@vger.kernel.org
Cc: Mimi Zohar <zohar@linux.ibm.com>,
Eric Biggers <ebiggers@kernel.org>,
Stefan Berger <stefanb@linux.ibm.com>,
linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v6 5/5] fsverity: update the documentation
Date: Fri, 18 Mar 2022 14:21:51 -0400 [thread overview]
Message-ID: <20220318182151.100847-6-zohar@linux.ibm.com> (raw)
In-Reply-To: <20220318182151.100847-1-zohar@linux.ibm.com>
Update the fsverity documentation related to IMA signature support.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
---
Documentation/filesystems/fsverity.rst | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst
index 1d831e3cbcb3..28a47488848e 100644
--- a/Documentation/filesystems/fsverity.rst
+++ b/Documentation/filesystems/fsverity.rst
@@ -74,8 +74,12 @@ authenticating the files is up to userspace. However, to meet some
users' needs, fs-verity optionally supports a simple signature
verification mechanism where users can configure the kernel to require
that all fs-verity files be signed by a key loaded into a keyring; see
-`Built-in signature verification`_. Support for fs-verity file hashes
-in IMA (Integrity Measurement Architecture) policies is also planned.
+`Built-in signature verification`_.
+
+IMA supports including fs-verity file digests and signatures in the
+IMA (Integrity Measurement Architecture) measurement list and
+verifying fs-verity based file signatures stored as security.ima
+xattrs, based on policy.
User API
========
@@ -653,13 +657,13 @@ weren't already directly answered in other parts of this document.
hashed and what to do with those hashes, such as log them,
authenticate them, or add them to a measurement list.
- IMA is planned to support the fs-verity hashing mechanism as an
- alternative to doing full file hashes, for people who want the
- performance and security benefits of the Merkle tree based hash.
- But it doesn't make sense to force all uses of fs-verity to be
- through IMA. As a standalone filesystem feature, fs-verity
- already meets many users' needs, and it's testable like other
- filesystem features e.g. with xfstests.
+ IMA supports the fs-verity hashing mechanism as an alternative
+ to doing full file hashes, for people who want the performance
+ and security benefits of the Merkle tree based hash. But it
+ doesn't make sense to force all uses of fs-verity to be through
+ IMA. As a standalone filesystem feature, fs-verity already meets
+ many users' needs, and it's testable like other filesystem
+ features e.g. with xfstests.
:Q: Isn't fs-verity useless because the attacker can just modify the
hashes in the Merkle tree, which is stored on-disk?
--
2.27.0
next prev parent reply other threads:[~2022-03-18 18:22 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-18 18:21 [PATCH v6 0/5] ima: support fs-verity digests and signatures Mimi Zohar
2022-03-18 18:21 ` [PATCH v6 1/5] fs-verity: define a function to return the integrity protected file digest Mimi Zohar
2022-03-18 18:21 ` [PATCH v6 2/5] ima: define a new template field named 'd-ngv2' and templates Mimi Zohar
2022-03-21 12:53 ` Stefan Berger
2022-03-21 19:48 ` Mimi Zohar
2022-03-21 20:46 ` Stefan Berger
2022-03-18 18:21 ` [PATCH v6 3/5] ima: permit fsverity's file digests in the IMA measurement list Mimi Zohar
2022-03-21 12:59 ` Stefan Berger
2022-03-21 19:54 ` Mimi Zohar
2022-03-18 18:21 ` [PATCH v6 4/5] ima: support fs-verity file digest based version 3 signatures Mimi Zohar
2022-03-21 13:10 ` Stefan Berger
2022-03-25 12:31 ` Mimi Zohar
2022-03-25 13:49 ` Stefan Berger
2022-03-18 18:21 ` Mimi Zohar [this message]
2022-03-18 20:55 ` [PATCH v6 5/5] fsverity: update the documentation Stefan Berger
2022-03-21 12:55 ` Mimi Zohar
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