diff options
author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2019-08-26 14:55:20 +1000 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-08-30 09:40:14 +1000 |
commit | 4f916593be9da38c5cf0d3a5c386b57beb70f422 (patch) | |
tree | 4355102b215462c3f8242b808cf640fa5b7ae113 | |
parent | da15c03b047dca891d37b9f4ef9ca14d84a6484f (diff) | |
download | linux-4f916593be9da38c5cf0d3a5c386b57beb70f422.tar.gz |
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 with TCEs which can cause early exit from the handler and leave 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. Fixes: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO") Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190826045520.92153-1-aik@ozlabs.ru
-rw-r--r-- | arch/powerpc/kvm/book3s_64_vio.c | 6 | ||||
-rw-r--r-- | 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 e99a14798ab0..c4b606fe73eb 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -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, diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c index f50bbeedfc66..b4f20f13b860 100644 --- a/arch/powerpc/kvm/book3s_64_vio_hv.c +++ b/arch/powerpc/kvm/book3s_64_vio_hv.c @@ -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, |