Re: [PATCH v2 06/14] iommu/mediatek: fix device leaks on probe()

On Tue, 2025-10-07 at 11:43 +0200, Johan Hovold wrote:

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Make sure to drop the references taken to the larb devices during probe on probe failure (e.g. probe deferral) and on driver unbind.

Note that commit 26593928564c ("iommu/mediatek: Add error path for loop of mm_dts_parse") fixed the leaks in a couple of error paths, but the references are still leaking on success and late failures.

Fixes: 0df4fabe208d ("iommu/mediatek: Add mt8173 IOMMU driver") Cc: stable@vger.kernel.org # 4.6 Cc: Yong Wu yong.wu@mediatek.com Acked-by: Robin Murphy robin.murphy@arm.com Signed-off-by: Johan Hovold johan@kernel.org

---

drivers/iommu/mtk_iommu.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 8d8e85186188..20a5ba80f983 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -1216,13 +1216,17 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m platform_device_put(plarbdev); }

•   if (!frst_avail_smicomm_node)
  

•           return -EINVAL;
  

•   if (!frst_avail_smicomm_node) {
  

•           ret = -EINVAL;
  

•           goto err_larbdev_put;
  

There already is a "platform_device_put(plarbdev);" at the end of "for" loop, then no need put_device for it outside the "for" loop or outside this function?

Thanks.

•   }
  
    pcommdev = of_find_device_by_node(frst_avail_smicomm_node);
    of_node_put(frst_avail_smicomm_node);
  

•   if (!pcommdev)
  

•           return -ENODEV;
  

•   if (!pcommdev) {
  

•           ret = -ENODEV;
  

•           goto err_larbdev_put;
  

•   }
    data->smicomm_dev = &pcommdev->dev;
  
    link = device_link_add(data->smicomm_dev, dev,
  

@@ -1230,7 +1234,8 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m platform_device_put(pcommdev); if (!link) { dev_err(dev, "Unable to link %s.\n", dev_name(data-

...

smicomm_dev));

•           return -EINVAL;
  

•           ret = -EINVAL;
  

•           goto err_larbdev_put;
    }
    return 0;
  
  

@@ -1402,8 +1407,12 @@ static int mtk_iommu_probe(struct platform_device *pdev) iommu_device_sysfs_remove(&data->iommu); out_list_del: list_del(&data->list);

•   if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_MM))
  

•   if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_MM)) {
            device_link_remove(data->smicomm_dev, dev);
  

•           for (i = 0; i < MTK_LARB_NR_MAX; i++)
  

•                   put_device(data->larb_imu[i].dev);
  

•   }
  

out_runtime_disable: pm_runtime_disable(dev); return ret; @@ -1423,6 +1432,9 @@ static void mtk_iommu_remove(struct platform_device *pdev) if (MTK_IOMMU_IS_TYPE(data->plat_data, MTK_IOMMU_TYPE_MM)) { device_link_remove(data->smicomm_dev, &pdev->dev); component_master_del(&pdev->dev, &mtk_iommu_com_ops);

•           for (i = 0; i < MTK_LARB_NR_MAX; i++)
  

•                   put_device(data->larb_imu[i].dev);
    }
    pm_runtime_disable(&pdev->dev);
    for (i = 0; i < data->plat_data->banks_num; i++) {
  

-- 2.49.1