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Subject[PATCH 5.10 091/120] KVM: x86: fix CPUID entries returned by KVM_GET_CPUID2 ioctl
From: Michael Roth <>

commit 181f494888d5b178ffda41bed965f187d5e5c432 upstream.

Recent commit 255cbecfe0 modified struct kvm_vcpu_arch to make
'cpuid_entries' a pointer to an array of kvm_cpuid_entry2 entries
rather than embedding the array in the struct. KVM_SET_CPUID and
KVM_SET_CPUID2 were updated accordingly, but KVM_GET_CPUID2 was missed.

As a result, KVM_GET_CPUID2 currently returns random fields from struct
kvm_vcpu_arch to userspace rather than the expected CPUID values. Fix
this by treating 'cpuid_entries' as a pointer when copying its
contents to userspace buffer.

Fixes: 255cbecfe0c9 ("KVM: x86: allocate vcpu->arch.cpuid_entries dynamically")
Cc: Vitaly Kuznetsov <>
Signed-off-by: Michael Roth <>
Message-Id: <>
Signed-off-by: Paolo Bonzini <>
Signed-off-by: Greg Kroah-Hartman <>
arch/x86/kvm/cpuid.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -320,7 +320,7 @@ int kvm_vcpu_ioctl_get_cpuid2(struct kvm
if (cpuid->nent < vcpu->arch.cpuid_nent)
goto out;
r = -EFAULT;
- if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
+ if (copy_to_user(entries, vcpu->arch.cpuid_entries,
vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
goto out;
return 0;

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