Re: [PATCH v3] ima: detect changes to the backing overlay file

[Eric Snowberg]

> On Oct 25, 2023, at 8:39 AM, Mimi Zohar <zohar@xxxxxxxxxxxxx> wrote:
> 
> Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for
> IMA") forced signature re-evaulation on every file access.
> 
> Instead of always re-evaluating the file's integrity, detect a change
> to the backing file, by comparing the cached file metadata with the
> backing file's metadata.  Verifying just the i_version has not changed
> is insufficient.  In addition save and compare the i_ino and s_dev
> as well.
> 
> Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>

I ran the file integrity tests that originally uncovered the need for 
"Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for 
IMA”). When the backing file is changed, file integrity remains.  For that 
part, feel free to add:

Tested-by: Eric Snowberg <eric.snowberg@xxxxxxxxxx>