[ 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@xxxxxxxxxxxxxxx # v4.11+
Fixes: 121f80ba68f1 ("KVM: PPC: VFIO: Add in-kernel acceleration for VFIO")
Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 9a3f2646ecc7e..07a8004c3c237 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 6821ead4b4ebc..eb8b11515a7ff 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,
--
2.20.1
