vcpu->arch.wbinvd_dirty_mask may still be used after freeing it,
corrupting memory. For example, the following call trace may set a bit
in an already freed cpu mask:
kvm_arch_vcpu_load
vcpu_load
vmx_free_vcpu_nested
vmx_free_vcpu
kvm_arch_vcpu_free
Fix this by deferring freeing of wbinvd_dirty_mask.
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ido Yariv <ido@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6c633de..9ec8c1d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7410,10 +7410,12 @@ void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
{
+ void *wbinvd_dirty_mask = vcpu->arch.wbinvd_dirty_mask;
+
kvmclock_reset(vcpu);
- free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
kvm_x86_ops->vcpu_free(vcpu);
+ free_cpumask_var(wbinvd_dirty_mask);
}
struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
--
2.5.5
--
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