From 9e38128f8bd1d4f2244d8a393bc5dc204a99a541 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Fri, 25 Mar 2022 14:21:39 +0100 Subject: [PATCH] KVM: x86: Avoid theoretical NULL pointer dereference in kvm_irq_delivery_to_apic_fast() commit 00b5f37189d24ac3ed46cb7f11742094778c46ce upstream. When kvm_irq_delivery_to_apic_fast() is called with APIC_DEST_SELF shorthand, 'src' must not be NULL. Crash the VM with KVM_BUG_ON() instead of crashing the host. Signed-off-by: Vitaly Kuznetsov Message-Id: <20220325132140.25650-3-vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/lapic.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 6c87032c928cb..5c7a033d39d13 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -987,6 +987,10 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, *r = -1; if (irq->shorthand == APIC_DEST_SELF) { + if (KVM_BUG_ON(!src, kvm)) { + *r = 0; + return true; + } *r = kvm_apic_set_irq(src->vcpu, irq, dest_map); return true; } -- 2.47.2