# RE: \[RFC\]\[PATCH v2 06/12\] diglim: Interfaces - digest\_list\_add, digest\_list\_del

- From: Roberto Sassu \<roberto.sassu@huawei.com\>
- Date: 2021-07-30 14:25:04 
- List: linux-integrity
- Page: https://ratatoskr.run/linux-integrity/2021/07/1463352
- Thread: https://ratatoskr.run/linux-integrity/2021/07/1458516/t.md

```text
> From: Mimi Zohar [mailto:zohar@linux.ibm.com]
> Sent: Friday, July 30, 2021 4:03 PM
> Hi Roberto,
> 
> On Fri, 2021-07-30 at 13:16 +0000, Roberto Sassu wrote:
> > > From: Mimi Zohar [mailto:zohar@linux.ibm.com]
> > > Sent: Friday, July 30, 2021 2:40 PM
> 
> > > "critical data", in this context, should probably be used for verifying
> > > the in memory file digests and other state information haven't been
> > > compromised.
> >
> > Actually, this is what we are doing currently. To keep the
> > implementation simple, once the file or the buffer are uploaded
> > to the kernel, they will not be modified, just accessed through
> > the indexes.
> 
> My main concern about digest lists is their integrity, from loading the
> digest lists to their being stored in memory.  A while back, there was
> some work on defining a write once memory allocator.  I don't recall
> whatever happened to it.  This would be a perfect usecase for that
> memory allocator.

Adding Igor in CC.

Regarding loading, everything uploaded to the kernel is carefully
evaluated. This should not be a concern. Regarding making them
read-only, probably if you can subvert digest lists you can also
remove the read-only protection (unless you use an hypervisor).

Thanks

Roberto

HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
Managing Director: Li Peng, Li Jian, Shi Yanli

> thanks,
> 
> Mimi

```