GICv5 supports up to 128 PPIs, but KVM currently implements only the
first 64, which contain the architected PPIs it supports.
An encoded PPI with an ID outside that range passes irq_is_ppi(),
which only checks the encoded interrupt type. vgic_get_vcpu_irq()
therefore looks it up in private_irqs[], where array_index_nospec()
clamps the out-of-range index to zero and aliases PPI 0.
Include the supported PPI range in irq_is_ppi() so that KVM interfaces
reject unsupported PPIs. Also reject an out-of-range PPI in the lookup
as a safeguard against callers bypassing the predicate.
Fixes: 4d591252ba ("KVM: arm64: gic-v5: Implement PPI interrupt injection")
Fixes: eb8bce08ec ("KVM: arm64: gic: Introduce interrupt type helpers")
Link: https://sashiko.dev/#/patchset/20260724104819.1296803-1-sascha.bischoff@arm.com?part=27
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/20260811150941.941295-4-sascha.bischoff@arm.com
Signed-off-by: Oliver Upton <oupton@kernel.org>
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