Re: [PATCH v3] mm/page_reporting: use system_freezable_wq to fix UAF during suspend

[Link Lin]

On Thu, Jul 23, 2026 at 2:15 AM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
>
> I suspect rest of work items we have, e.g. update_balloon_stats_work/update_balloon_size_work
> all have issues around freeze/restore and error handling.
>
> --
> MST
>

Hi Michael,

We have indeed discovered a kernel crash in update_balloon_stats_work
after the balloon driver failed to resume and initialize in our
production fleet.

Alex Wilkins <ahwilkins@xxxxxxxxxx> diagnosed, root caused, and
reported this vulnerability. I am currently drafting and testing a
2-patch series to gracefully unregister callbacks and cancel work
items on resume failure so that the VM continues running without the
balloon driver instead of crashing with a kernel panic.

I wanted to follow up and let you know that we are actively working on
this. I will send out the patches to the list as soon as they are
sufficiently tested.

Best,
Link