Re: [PATCH v2 2/4] KVM: arm64: vgic: Don't leak the SPI array when init is retried

[Marc Zyngier <maz@kernel.org>]

On Tue, 18 Aug 2026 14:22:09 +0100,
Fuad Tabba <fuad.tabba@linux.dev> wrote:
> 
> Hi again Marc,
> 
> On Mon, 17 Aug 2026 at 19:40, Fuad Tabba <fuad.tabba@linux.dev> wrote:
> ...
> > > I really don't want to have to think about the intermediate state.
> >
> > Agreed. I'll drop the idempotent version I sketched and do teardown
> > and reinit instead.
> 
> Here are my thoughts. Three patches, all fixes.
> 
> vgic_init() will undo what it created when it fails, so
> KVM_DEV_ARM_VGIC_CTRL_INIT is all or nothing and a retry starts from
> scratch. Same thing you asked Karl for on the redistributor rollback
> [1].
> 
> That drops the count check I sketched. vgic_v4_init()'s early return
> stays, since vgic_its_create() still calls it for an ITS created after
> init.
> 
> irq-gic-v4.c goes first, as two patches. It removes the domains and
> frees the fwnodes without clearing the pointers, at four sites, and
> the teardown above makes that reachable on a path where it was not.
> The second is a leak in the same error path: when
> its_alloc_vcpu_sgis() fails partway, the SGI domains already allocated
> below it are never unwound.
> 
> What do you think?

Hard to picture when described like this. Please post the patches!

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.