Update the fsverity documentation related to IMA signature support.
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
Documentation/filesystems/fsverity.rst | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst
index 1d831e3cbcb3..c1d355f17a54 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`_.
+
+The Integrity Measurement Architecture (IMA) supports including
+fs-verity file digests and signatures in the IMA measurement list
+and verifying fs-verity based file signatures stored as security.ima
+xattrs, based on policy.
User API
========
@@ -653,12 +657,12 @@ 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
+ IMA supports the fs-verity hashing mechanism as an alternative
+ to full file hashes, for those who want the performance and
+ security benefits of the Merkle tree based hash. However, it
+ doesn't make sense to force all uses of fs-verity to be through
+ IMA. fs-verity already meets many users' needs even as a
+ standalone filesystem feature, 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
--
2.27.0
