Commit ef693a84 authored by Guenter Roeck's avatar Guenter Roeck Committed by Joerg Roedel
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iommu/mediatek: Validate number of phandles associated with "mediatek,larbs" 



Fix the smatch warnings:
drivers/iommu/mtk_iommu.c:878 mtk_iommu_mm_dts_parse() error: uninitialized
symbol 'larbnode'.

If someone abuse the dtsi node(Don't follow the definition of dt-binding),
for example "mediatek,larbs" is provided as boolean property, "larb_nr"
will be zero and cause abnormal.

To fix this problem and improve the code safety, add some checking
for the invalid input from dtsi, e.g. checking the larb_nr/larbid valid
range, and avoid "mediatek,larb-id" property conflicts in the smi-larb
nodes.

Fixes: d2e9a110 ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarGuenter Roeck <groeck@chromium.org>
Signed-off-by: default avatarYong Wu <yong.wu@mediatek.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: default avatarMatthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/20221018024258.19073-5-yong.wu@mediatek.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 26593928

drivers/iommu/mtk_iommu.c

+12 −0
Original line number Diff line number Diff line
@@ -1062,6 +1062,8 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m 
	larb_nr = of_count_phandle_with_args(dev->of_node, "mediatek,larbs", NULL);

	if (larb_nr < 0)

		return larb_nr;

	if (larb_nr == 0 || larb_nr > MTK_LARB_NR_MAX)

		return -EINVAL;



	for (i = 0; i < larb_nr; i++) {

		u32 id;
@@ -1080,6 +1082,11 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m 
		ret = of_property_read_u32(larbnode, "mediatek,larb-id", &id);

		if (ret)/* The id is consecutive if there is no this property */

			id = i;

		if (id >= MTK_LARB_NR_MAX) {

			of_node_put(larbnode);

			ret = -EINVAL;

			goto err_larbdev_put;

		}



		plarbdev = of_find_device_by_node(larbnode);

		of_node_put(larbnode);
@@ -1087,6 +1094,11 @@ static int mtk_iommu_mm_dts_parse(struct device *dev, struct component_match **m 
			ret = -ENODEV;

			goto err_larbdev_put;

		}

		if (data->larb_imu[id].dev) {

			platform_device_put(plarbdev);

			ret = -EEXIST;

			goto err_larbdev_put;

		}

		data->larb_imu[id].dev = &plarbdev->dev;



		if (!plarbdev->dev.driver) {