Re: [PATCH net] net: pse-pd: scope pse_control regulator handle to kref lifetime

[Carlo Szelinsky]

On Wed, 24 Jun 2026 16:12:51 +0100, Simon Horman wrote:
> This is an AI-generated review of your patch. The human sending this
> email has considered the AI review valid, or at least plausible.
[...]
> [High]
> Does this fix the use-after-free completely, or only the regulator-put
> part of it?
[...]
> Would a more complete fix also need pse_controller_unregister() to
> drain outstanding pse_control references, or have pse_control hold a
> refcount on pcdev, so that psec cannot outlive pcdev->pi and pcdev?

Thanks, the review is correct. This patch only fixes the regulator
handle. In the same unbind-while-held case __pse_control_release()
also reads psec->pcdev->pi[] and psec->pcdev->owner after
pse_controller_unregister() has freed pcdev->pi, so those are still
use-after-free reads on their own.

That wider problem is exactly what you describe: the controller does
not drain its outstanding pse_control references on unregister. It is
fixed by draining them, which is what the PSE notifier series does --
PSE_UNREGISTERED drops every phydev->psec before pse_release_pis()
frees pcdev->pi. This patch is patch 1 of that series (by Corey
Leavitt); the rest targets net-next and is deferred until it reopens:

  https://lore.kernel.org/netdev/20260620112440.1734404-1-github@xxxxxxxxxxxx/

Jakub suggested sending this one to net on its own since it is a fix,
so it is here without the notifier patches. My v1 commit message
overclaimed by saying it makes __pse_control_release() correct
regardless of the controller's devres state, which is only true for
the regulator handle. I have reworded it in v2 to scope it to the
regulator put and to point at the series for the wider lifetime fix.

Does you agree? Another option would be to wait for the entire series.

cheers Carlo