[ 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>
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,
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,