Messages in this thread | | | Subject | Re: [PATCH v2 0/3] initramfs: add support for xattrs in the initial ram disk | From | Mimi Zohar <> | Date | Sun, 12 May 2019 20:02:30 -0400 |
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On Sun, 2019-05-12 at 17:31 +0200, Dominik Brodowski wrote: > On Sun, May 12, 2019 at 08:52:47AM -0400, Mimi Zohar wrote:
> > It's too late. The /init itself should be signed and verified. > > Could you elaborate a bit more about the threat model, and why deferring > this to the initramfs is too late?
The IMA policy defines a number of different methods of identifying which files to measure, appraise, audit.[1] Without xattrs, the granularity of the policy rules is severely limited. Without xattrs, a filesystem is either in policy, or not.
With an IMA policy rule requiring rootfs (tmpfs) files to be verified, then /init needs to be properly labeled, otherwise /init will fail to execute.
Mimi
[1] Documentation/ABI/testing/ima_policy
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