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

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[ 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 <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Alexey Kardashevskiy 2019-09-03 16:16:27 -04:00 committed by Greg Kroah-Hartman
parent d5054c17d9
commit 06ab420a84
2 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/powerpc/kvm/book3s_64_vio.c
View File

@ -566,8 +566,10 @@ 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,

6
arch/powerpc/kvm/book3s_64_vio_hv.c
View File

@ -475,8 +475,10 @@ 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,