iommu/mediatek-v1: fix device leak on probe_device()

commit c77ad28bfee0df9cbc719eb5adc9864462cfb65b upstream.

Make sure to drop the reference taken to the iommu platform device when
looking up its driver data during probe_device().

Fixes: b17336c55d89 ("iommu/mediatek: add support for mtk iommu generation one HW")
Cc: stable@vger.kernel.org	# 4.8
Cc: Honghui Zhang <honghui.zhang@mediatek.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 02668fd3404f19fa02c2400de70dcc38316571cc..2e64755df3d0d5c5e5f28d014c5ce6c94b2db434 100644 (file)
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -393,6 +393,8 @@ static int mtk_iommu_create_mapping(struct device *dev,
                        return -EINVAL;
 
                dev_iommu_priv_set(dev, platform_get_drvdata(m4updev));
+
+               put_device(&m4updev->dev);
        }
 
        ret = iommu_fwspec_add_ids(dev, args->args, 1);