iommu: Check return of __iommu_attach_device()

Currently iommu_create_device_direct_mappings() is called
without checking the return of __iommu_attach_device(). This
may result in failures in iommu driver if dev attach returns
error.

Fixes: ce574c27 ("iommu: Move iommu_group_create_direct_mappings() out of iommu_group_add_device()")
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20201119165846.34180-1-shameerali.kolothum.thodi@huawei.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/iommu/iommu.c

@@ -264,16 +264,18 @@ int iommu_probe_device(struct device *dev)
 	 */
 	iommu_alloc_default_domain(group, dev);
 
-	if (group->default_domain)
+	if (group->default_domain) {
 		ret = __iommu_attach_device(group->default_domain, dev);
+		if (ret) {
+			iommu_group_put(group);
+			goto err_release;
+		}
+	}
 
 	iommu_create_device_direct_mappings(group, dev);
 
 	iommu_group_put(group);
 
-	if (ret)
-		goto err_release;
-
 	if (ops->probe_finalize)
 		ops->probe_finalize(dev);