Re: [PATCH v4 0/8] ima: support fs-verity digests and signatures

[Eric Biggers]

On Mon, Feb 07, 2022 at 08:41:32PM -0500, Mimi Zohar wrote:
> Support for including fs-verity file digests and signatures in the IMA
> measurement list as well as verifying the fs-verity file digest based
> signatures, both based on IMA policy rules, was discussed prior to
> fs-verity being upstreamed[1,2].
> 
> Support for including fs-verity file digests in the 'd-ng' template field
> is based on a new policy rule option named 'digest_type=verity'.  A new
> template field named 'd-type' as well as a new template named 'ima-ngv2'
> are defined to differentiate between the regular IMA file hashes from the
> fs-verity file digests (tree-hash based file hashes) stored in the 'd-ng'
> template field.
> 
> Support for verifying fs-verity based file signatures stored in the
> 'security.ima' xattr is similarly based on the policy rule option
> 'digest_type=verity'.
> 
> To differentiate IMA from fs-verity file signatures a new xattr_type
> named IMA_VERITY_DIGSIG is defined.  Signature version 3, which is a hash
> of the ima_file_id struct, disambiguates the signatures stored as
> 'security.ima' xattr.  fs-verity only supports the new signature format
> (version 3).  To prevent abuse of the different signature formats, policy
> rules must be limited to a specific signature version.
> 
> [1] https://events19.linuxfoundation.org/wp-content/uploads/2017/11/fs-verify_Mike-Halcrow_Eric-Biggers.pdf
> [2] Documentation/filesystems/fsverity.rst

What does this patchset apply to?  I'm no longer able to apply it.  I tried
both v5.17-rc3, and the next-integrity branch of
https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git.

- Eric