Re: [PATCH v7 4/6] iommu/mediatek: Validate number of phandles associated with "mediatek,larbs"
From: Matthias Brugger <matthias.bgg@gmail.com>
Date: 2022-11-22 16:44:23
Also in:
linux-iommu, linux-mediatek, lkml
On 18/10/2022 04:42, Yong Wu wrote:
From: Guenter Roeck <groeck@chromium.org>
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: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with the MM TYPE")
Reported-by: kernel test robot <redacted>
Reported-by: Dan Carpenter <redacted>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
quoted hunk ↗ jump to hunk
--- drivers/iommu/mtk_iommu.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 912322494bc0..9cbff48f03c0 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c@@ -1050,6 +1050,8 @@ 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;@@ -1068,6 +1070,11 @@ 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);@@ -1075,6 +1082,11 @@ 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) {
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