[PATCH v4 0/3] initramfs: add support for xattrs in the initial ram disk

[Rob Landley]

On 6/3/19 4:31 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 including file metadata as additional files named
>> METADATA!!!, for each file added to the ram disk. The CPIO parser in the
>> kernel recognizes these special files from the file name, and calls the
>> appropriate parser to add metadata to the previously extracted file. It has
>> been proposed to use bit 17:16 of the file mode as a way to recognize files
>> with metadata, but both the kernel and the cpio tool declare the file mode
>> as unsigned short.
>
> Any opinion on this patch set?
> 
> Thanks
> 
> Roberto

Sorry, I've had the window open since you posted it but haven't gotten around to
it. I'll try to build it later today.

It does look interesting, and I have no objections to the basic approach. I
should be able to add support to toybox cpio over a weekend once I've got the
kernel doing it to test against.

Rob