Re: [PATCH] mailbox: pcc: Free the channel before unmapping the shared memory

[Breno Leitao <leitao@debian.org>]

Hello Adam,

On Sat, Aug 15, 2026 at 11:58:16PM -0400, Adam Young wrote:
> On 8/12/26 08:36, Breno Leitao wrote:
> > Free the channel first, before the memory unmap. mbox_free_channel()
> > calls pcc_shutdown(), which frees the platform interrupt, and then unmap
> > shared memory.
>
> I posted a related fix undere the MCTP PCC Driver changes.
>
> This fix is necessary but not sufficient to deal with the race conditions.
> Take a look at the series of patches under here:
>
> https://lore.kernel.org/all/20260721175258.87600-1-admiyo@os.amperecomputing.com/

That looks like a much bigger series, with new features, open discussions,
Nacks, and already 45 revisions.

This curent fix is only meant to address a real problem (user after
free) I am hitting in production systems.

My suggestion is that we get this real issue unblocked, even if not
complete, while you keep working on your larger series.

Thanks,
--breno