Patch "iommu/mediatek: Add error path for loop of mm_dts_parse" has been added to the 6.0-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    iommu/mediatek: Add error path for loop of mm_dts_parse

to the 6.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     iommu-mediatek-add-error-path-for-loop-of-mm_dts_par.patch
and it can be found in the queue-6.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 1d6cbddae1ae3a56d5f33ad85264fdd126ba61ba
Author: Yong Wu <yong.wu@xxxxxxxxxxxx>
Date:   Tue Oct 18 10:42:55 2022 +0800

    iommu/mediatek: Add error path for loop of mm_dts_parse
    
    [ Upstream commit 26593928564cf5b576ff05d3cbd958f57c9534bb ]
    
    The mtk_iommu_mm_dts_parse will parse the smi larbs nodes. if the i+1
    larb is parsed fail, we should put_device for the i..0 larbs.
    
    There are two places need to comment:
    1) The larbid may be not linear mapping, we should loop whole
       the array in the error path.
    2) I move this line position: "data->larb_imu[id].dev = &plarbdev->dev;"
       before "if (!plarbdev->dev.driver)", That means set
       data->larb_imu[id].dev before the error path. then we don't need
       "platform_device_put(plarbdev)" again in probe_defer case. All depend
       on "put_device" of the error path in error cases.
    
    Fixes: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
    Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
    Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
    Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>
    Link: https://lore.kernel.org/r/20221018024258.19073-4-yong.wu@xxxxxxxxxxxx
    Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index ce9288695f9b..39f4c79e9c71 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -1053,8 +1053,10 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 		u32 id;
 
 		larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i);
-		if (!larbnode)
-			return -EINVAL;
+		if (!larbnode) {
+			ret = -EINVAL;
+			goto err_larbdev_put;
+		}
 
 		if (!of_device_is_available(larbnode)) {
 			of_node_put(larbnode);
@@ -1067,14 +1069,16 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 
 		plarbdev = of_find_device_by_node(larbnode);
 		of_node_put(larbnode);
-		if (!plarbdev)
-			return -ENODEV;
+		if (!plarbdev) {
+			ret = -ENODEV;
+			goto err_larbdev_put;
+		}
+		data->larb_imu[id].dev = &plarbdev->dev;
 
 		if (!plarbdev->dev.driver) {
-			platform_device_put(plarbdev);
-			return -EPROBE_DEFER;
+			ret = -EPROBE_DEFER;
+			goto err_larbdev_put;
 		}
-		data->larb_imu[id].dev = &plarbdev->dev;
 
 		component_match_add(dev, match, component_compare_dev, &plarbdev->dev);
 		platform_device_put(plarbdev);
@@ -1109,6 +1113,15 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m
 		return -EINVAL;
 	}
 	return 0;
+
+err_larbdev_put:
+	/* id may be not linear mapping, loop whole the array */
+	for (i = MTK_LARB_NR_MAX - 1; i >= 0; i++) {
+		if (!data->larb_imu[i].dev)
+			continue;
+		put_device(data->larb_imu[i].dev);
+	}
+	return ret;
 }
 
 static int mtk_iommu_probe(struct platform_device *pdev)