[PATCH 1/5] KVM: arm64: Don't leak PFN when kvm_translate_vncr() races MMU notifier

[Oliver Upton <oupton@kernel.org>]

In the case that kvm_translate_vncr() races with an MMU notifier the
early return does not release a reference on the faulted in PFN. Add
the necessary call to kvm_release_faultin_page() for the unused PFN.

Cc: stable@vger.kernel.org
Fixes: 069a05e535496 ("KVM: arm64: nv: Handle VNCR_EL2-triggered faults")
Reported-by: Sashiko (local):gemini-3.1-pro
Signed-off-by: Oliver Upton <oupton@kernel.org>
---
 arch/arm64/kvm/nested.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 883b6c1008fb..4fa82e96454d 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -1326,8 +1326,10 @@ static int kvm_translate_vncr(struct kvm_vcpu *vcpu, bool *is_gmem)
 	}
 
 	scoped_guard(write_lock, &vcpu->kvm->mmu_lock) {
-		if (mmu_invalidate_retry(vcpu->kvm, mmu_seq))
+		if (mmu_invalidate_retry(vcpu->kvm, mmu_seq)) {
+			kvm_release_faultin_page(vcpu->kvm, page, true, false);
 			return -EAGAIN;
+		}
 
 		vt->gva = va;
 		vt->hpa = pfn << PAGE_SHIFT;
-- 
2.47.3