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

commit 57d72e159b60456c8bb281736c02ddd3164037aa upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 64f1eb8..347aaaa 100644 (file)
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1541,13 +1541,15 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
                return -ENOMEM;
 
        arm_smmu_ops.pgsize_bitmap = pgtbl_cfg.pgsize_bitmap;
-       smmu_domain->pgtbl_ops = pgtbl_ops;
 
        ret = finalise_stage_fn(smmu_domain, &pgtbl_cfg);
-       if (IS_ERR_VALUE(ret))
+       if (IS_ERR_VALUE(ret)) {
                free_io_pgtable_ops(pgtbl_ops);
+               return ret;
+       }
 
-       return ret;
+       smmu_domain->pgtbl_ops = pgtbl_ops;
+       return 0;
 }
 
 static struct arm_smmu_group *arm_smmu_group_get(struct device *dev)