path: root/virt
diff options
authorJim Mattson <jmattson@google.com>2016-07-08 15:36:06 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-08-20 18:09:18 +0200
commit144941bd9907d0e616229f0b6dddcad512030407 (patch)
treeebeac52da186441da023f70c3c95dafb8d0016e6 /virt
parent6bd2820f906f75c4a05484a5b446e50a1f1b0e34 (diff)
KVM: nVMX: Fix memory corruption when using VMCS shadowing
commit 2f1fe81123f59271bddda673b60116bde9660385 upstream. When freeing the nested resources of a vcpu, there is an assumption that the vcpu's vmcs01 is the current VMCS on the CPU that executes nested_release_vmcs12(). If this assumption is violated, the vcpu's vmcs01 may be made active on multiple CPUs at the same time, in violation of Intel's specification. Moreover, since the vcpu's vmcs01 is not VMCLEARed on every CPU on which it is active, it can linger in a CPU's VMCS cache after it has been freed and potentially repurposed. Subsequent eviction from the CPU's VMCS cache on a capacity miss can result in memory corruption. It is not sufficient for vmx_free_vcpu() to call vmx_load_vmcs01(). If the vcpu in question was last loaded on a different CPU, it must be migrated to the current CPU before calling vmx_load_vmcs01(). Signed-off-by: Jim Mattson <jmattson@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'virt')
1 files changed, 2 insertions, 0 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 510df220d1b5..336ed267c407 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -142,6 +142,7 @@ int vcpu_load(struct kvm_vcpu *vcpu)
return 0;
void vcpu_put(struct kvm_vcpu *vcpu)
@@ -151,6 +152,7 @@ void vcpu_put(struct kvm_vcpu *vcpu)
static void ack_flush(void *_completed)