Re: [PATCH] irqchip/gic-v4: Don't allow a VMOVP on a dying VPE

From: Thomas Gleixner
Date: Wed Oct 02 2024 - 18:17:20 EST


On Wed, Oct 02 2024 at 21:49, Marc Zyngier wrote:
> Kunkun Jiang reports that there is a small window of opportunity for
> userspace to force a change of affinity for a VPE while the VPE has
> already been unmapped, but the corresponding doorbell interrupt still
> visible in /proc/irq/.
>
> Plug the race by checking the value of vmapp_count, which tracks whether
> the VPE is mapped ot not, and returning an error in this case.
>
> This involves making vmapp_count common to both GICv4.1 and its v4.0
> ancestor.
>
> Reported-by: Kunkun Jiang <jiangkunkun@xxxxxxxxxx>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> Link: https://lore.kernel.org/r/c182ece6-2ba0-ce4f-3404-dba7a3ab6c52@xxxxxxxxxx

I assume this wants a Fixes: tag and a cc: stable, no?

Thanks,

tglx