Re: [PATCH v3 0/6] Composefs: an opportunistically sharing verified image filesystem

[Miklos Szeredi]

On Mon, 6 Feb 2023 at 18:16, Amir Goldstein <amir73il@xxxxxxxxx> wrote:

> it's not overlay{erofs+erofs}
> it's overlay{erofs+ext4} (or another fs-verity [1] supporting fs)
> the lower layer is a mutable fs with /objects/ dir containing
> the blobs.
>
> The way to ensure the integrity of erofs is to setup dm-verity at
> erofs mount time.
>
> The way to ensure the integrity of the blobs is to store an fs-verity
> signature of each blob file in trusted.overlay.verify xattr on the
> metacopy and for overlayfs to enable fsverity on the blob file before
> allowing access to the lowerdata.
>
> At least this is my understanding of the security model.

So this should work out of the box, right?

Thanks,
Miklos