From db1841a2dd4c84f390c3e0ed15d6a4ea601433e9 Mon Sep 17 00:00:00 2001 From: Alexey Kardashevskiy Date: Tue, 3 Sep 2019 16:16:27 -0400 Subject: [PATCH] KVM: PPC: Book3S: Fix incorrect guest-to-user-translation error handling [ Upstream commit ddfd151f3def9258397fcde7a372205a2d661903 ] 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: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO") Signed-off-by: Alexey Kardashevskiy Signed-off-by: Paul Mackerras Signed-off-by: Sasha Levin --- arch/powerpc/kvm/book3s_64_vio.c | 6 ++++-- arch/powerpc/kvm/book3s_64_vio_hv.c | 6 ++++-- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index 9a3f264..07a8004 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -602,8 +602,10 @@ long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, if (kvmppc_gpa_to_ua(vcpu->kvm, tce & ~(TCE_PCI_READ | TCE_PCI_WRITE), - &ua, NULL)) - return H_PARAMETER; + &ua, NULL)) { + ret = H_PARAMETER; + goto unlock_exit; + } list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c index 6821ead..eb8b115 100644 --- a/arch/powerpc/kvm/book3s_64_vio_hv.c +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c @@ -528,8 +528,10 @@ long kvmppc_rm_h_put_tce_indirect(struct kvm_vcpu *vcpu, ua = 0; if (kvmppc_gpa_to_ua(vcpu->kvm, tce & ~(TCE_PCI_READ | TCE_PCI_WRITE), - &ua, NULL)) - return H_PARAMETER; + &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, -- 2.7.4