iommu/arm-smmu-v3: Don't free page table ops twice

Kasan reports a double free when finalise_stage_fn fails: the io_pgtable
ops are freed by arm_smmu_domain_finalise and then again by
arm_smmu_domain_free. Prevent this by leaving pgtbl_ops empty on failure.

Cc: <stable@vger.kernel.org>
Fixes: 48ec83bcbcf5 ("iommu/arm-smmu: Add initial driver support for ARM SMMUv3 devices")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index f122071..db4281d 100644 (file)
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1698,13 +1698,15 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
        domain->pgsize_bitmap = pgtbl_cfg.pgsize_bitmap;
        domain->geometry.aperture_end = (1UL << ias) - 1;
        domain->geometry.force_aperture = true;
-       smmu_domain->pgtbl_ops = pgtbl_ops;
 
        ret = finalise_stage_fn(smmu_domain, &pgtbl_cfg);
-       if (ret < 0)
+       if (ret < 0) {
                free_io_pgtable_ops(pgtbl_ops);
+               return ret;
+       }
 
-       return ret;
+       smmu_domain->pgtbl_ops = pgtbl_ops;
+       return 0;
 }
 
 static __le64 *arm_smmu_get_step_for_sid(struct arm_smmu_device *smmu, u32 sid)