Re: [PATCH v2 0/3] initramfs: add support for xattrs in the initial ram disk

[Rob Landley]

On 5/9/19 6:24 AM, Roberto Sassu wrote:
> This patch set aims at solving the following use case: appraise files from
> the initial ram disk. To do that, IMA checks the signature/hash from the
> security.ima xattr. Unfortunately, this use case cannot be implemented
> currently, as the CPIO format does not support xattrs.
> 
> This proposal consists in marshaling pathnames and xattrs in a file called
> .xattr-list. They are unmarshaled by the CPIO parser after all files have
> been extracted.

So it's in-band signalling that has a higher peak memory requirement.

> The difference with another proposal
> (https://lore.kernel.org/patchwork/cover/888071/) is that xattrs can be
> included in an image without changing the image format, as opposed to
> defining a new one. As seen from the discussion, if a new format has to be
> defined, it should fix the issues of the existing format, which requires
> more time.

So you've explicitly chosen _not_ to address Y2038 while you're there.

Rob