Re: [RFC][PATCH 2/5] fsverity: Revalidate built-in signatures at file open

Eric Biggers
2021-11-12T19:15:07Z

On Fri, Nov 12, 2021 at 01:44:08PM +0100, Roberto Sassu wrote:
> Fsverity signatures are validated only upon request by the user by setting
> the requirement through procfs or sysctl.
>
> However, signatures are validated only when the fsverity-related
> initialization is performed on the file. If the initialization happened
> while the signature requirement was disabled, the signature is not
> validated again.

I'm not sure this really matters. If someone has started using a verity file
before the require_signatures sysctl was set, then there is already a race
condition; this patch doesn't fix that. Don't you need to set the
require_signatures sysctl early enough anyway?

- Eric