Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ddfd151f authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Paul Mackerras
Browse files

KVM: PPC: Book3S: Fix incorrect guest-to-user-translation error handling 



H_PUT_TCE_INDIRECT handlers receive a page with up to 512 TCEs from
a guest. Although we verify correctness of TCEs before we do anything
with the existing tables, there is a small window when a check in
kvmppc_tce_validate might pass and right after that the guest alters
the page of TCEs, causing an early exit from the handler and leaving
srcu_read_lock(&vcpu->kvm->srcu) (virtual mode) or lock_rmap(rmap)
(real mode) locked.

This fixes the bug by jumping to the common exit code with an appropriate
unlock.

Cc: stable@vger.kernel.org # v4.11+
Fixes: 121f80ba ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO")
Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent e4427372

arch/powerpc/kvm/book3s_64_vio.c

+4 −2
Original line number Diff line number Diff line
@@ -660,8 +660,10 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, 
		}

		tce = be64_to_cpu(tce);



		if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua))

			return H_PARAMETER;

		if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) {

			ret = H_PARAMETER;

			goto unlock_exit;

		}



		list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {

			ret = kvmppc_tce_iommu_map(vcpu->kvm, stt,

arch/powerpc/kvm/book3s_64_vio_hv.c

+4 −2
Original line number Diff line number Diff line
@@ -556,8 +556,10 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu, 
		unsigned long tce = be64_to_cpu(((u64 *)tces)[i]);



		ua = 0;

		if (kvmppc_rm_tce_to_ua(vcpu->kvm, tce, &ua, NULL))

			return H_PARAMETER;

		if (kvmppc_rm_tce_to_ua(vcpu->kvm, tce, &ua, NULL)) {

			ret = H_PARAMETER;

			goto unlock_exit;

		}



		list_for_each_entry_lockless(stit, &stt->iommu_tables, next) {

			ret = kvmppc_rm_tce_iommu_map(vcpu->kvm, stt,