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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2018-08-22 12:18:28 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-10-17 00:29:43 +0200 |
| commit | 9170200ec0ebad70e5b9902bc93e2b1b11456a3b (patch) | |
| tree | 2a935ca68f0dea412ba37fa77380cd6306583804 /arch/x86/kvm/hyperv.c | |
| parent | 0624fca9512d08cbd9b5d098d904c840d3432404 (diff) | |
| download | linux-9170200ec0ebad70e5b9902bc93e2b1b11456a3b.tar.bz2 | |
KVM: x86: hyperv: enforce vp_index < KVM_MAX_VCPUS
Hyper-V TLFS (5.0b) states:
> Virtual processors are identified by using an index (VP index). The
> maximum number of virtual processors per partition supported by the
> current implementation of the hypervisor can be obtained through CPUID
> leaf 0x40000005. A virtual processor index must be less than the
> maximum number of virtual processors per partition.
Forbid userspace to set VP_INDEX above KVM_MAX_VCPUS. get_vcpu_by_vpidx()
can now be optimized to bail early when supplied vpidx is >= KVM_MAX_VCPUS.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/hyperv.c')
| -rw-r--r-- | arch/x86/kvm/hyperv.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 01d209ab5481..0cd597b0f754 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -132,8 +132,10 @@ static struct kvm_vcpu *get_vcpu_by_vpidx(struct kvm *kvm, u32 vpidx) struct kvm_vcpu *vcpu = NULL; int i; - if (vpidx < KVM_MAX_VCPUS) - vcpu = kvm_get_vcpu(kvm, vpidx); + if (vpidx >= KVM_MAX_VCPUS) + return NULL; + + vcpu = kvm_get_vcpu(kvm, vpidx); if (vcpu && vcpu_to_hv_vcpu(vcpu)->vp_index == vpidx) return vcpu; kvm_for_each_vcpu(i, vcpu, kvm) @@ -1044,7 +1046,7 @@ static int kvm_hv_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host) switch (msr) { case HV_X64_MSR_VP_INDEX: - if (!host) + if (!host || (u32)data >= KVM_MAX_VCPUS) return 1; hv->vp_index = (u32)data; break; |