| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.18 22/67] KVM: x86: fix typo in __try_cmpxchg_user causing non-atomicness | Date | Fri, 3 Jun 2022 19:43:23 +0200 |
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From: Maxim Levitsky <mlevitsk@redhat.com>
commit 33fbe6befa622c082f7d417896832856814bdde0 upstream.
This shows up as a TDP MMU leak when running nested. Non-working cmpxchg on L0 relies makes L1 install two different shadow pages under same spte, and one of them is leaked.
Fixes: 1c2361f667f36 ("KVM: x86: Use __try_cmpxchg_user() to emulate atomic accesses") Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20220512101420.306759-1-mlevitsk@redhat.com> Reviewed-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- arch/x86/kvm/x86.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7268,7 +7268,7 @@ static int emulator_cmpxchg_emulated(str goto emul_write; hva = kvm_vcpu_gfn_to_hva(vcpu, gpa_to_gfn(gpa)); - if (kvm_is_error_hva(addr)) + if (kvm_is_error_hva(hva)) goto emul_write; hva += offset_in_page(gpa);
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