From: Jan H. Schönherr <jschoenh@amazon.de>
Date: Thu, 7 Sep 2017 18:02:48 +0000 (+0100)
Subject: KVM: Don't accept obviously wrong gsi values via KVM_IRQFD
X-Git-Tag: v6.6-pxa1908~15770^2~11
X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=36ae3c0a36b7456432fedce38ae2f7bd3e01a563;p=linux.git

KVM: Don't accept obviously wrong gsi values via KVM_IRQFD

We cannot add routes for gsi values >= KVM_MAX_IRQ_ROUTES -- see
kvm_set_irq_routing(). Hence, there is no sense in accepting them
via KVM_IRQFD. Prevent them from entering the system in the first
place.

Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index f2ac53ab8243..c608ab495282 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -565,6 +565,8 @@ kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
 {
 	if (args->flags & ~(KVM_IRQFD_FLAG_DEASSIGN | KVM_IRQFD_FLAG_RESAMPLE))
 		return -EINVAL;
+	if (args->gsi >= KVM_MAX_IRQ_ROUTES)
+		return -EINVAL;
 
 	if (args->flags & KVM_IRQFD_FLAG_DEASSIGN)
 		return kvm_irqfd_deassign(kvm, args);