From mboxrd@z Thu Jan 1 00:00:00 1970 From: christoffer.dall@linaro.org (Christoffer Dall) Date: Tue, 9 Dec 2014 16:44:03 +0100 Subject: [PATCH 4/5] arm/arm64: KVM: Don't allow creating VCPUs after vgic_initialized In-Reply-To: <1418139844-27892-1-git-send-email-christoffer.dall@linaro.org> References: <1418139844-27892-1-git-send-email-christoffer.dall@linaro.org> Message-ID: <1418139844-27892-5-git-send-email-christoffer.dall@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org When the vgic initializes its internal state it does so based on the number of VCPUs available at the time. If we allow KVM to create more VCPUs after the VGIC has been initialized, we are likely to error out in unfortunate ways later, perform buffer overflows etc. Cc: Eric Auger Signed-off-by: Christoffer Dall --- This replaces Eric Auger's previous patch (https://lists.cs.columbia.edu/pipermail/kvmarm/2014-December/012646.html), because it fits better with testing to include it in this series and I realized that we need to add a check against irqchip_in_kernel() as well. arch/arm/kvm/arm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index a9d005f..d4da244 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -213,6 +213,11 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id) int err; struct kvm_vcpu *vcpu; + if (irqchip_in_kernel(kvm) && vgic_initialized(kvm)) { + err = -EBUSY; + goto out; + } + vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL); if (!vcpu) { err = -ENOMEM; -- 2.1.2.330.g565301e.dirty