[PATCH AUTOSEL 5.10 15/16] drm/exynos: fix a potential error pointer dereference

[PATCH AUTOSEL 5.10 15/16] drm/exynos: fix a potential error pointer dereference

[Sasha Levin]

From: Xiang Yang <xiangyang3@huawei.com>

[ Upstream commit 73bf1c9ae6c054c53b8e84452c5e46f86dd28246 ]

Smatch reports the warning below:
drivers/gpu/drm/exynos/exynos_hdmi.c:1864 hdmi_bind()
error: 'crtc' dereferencing possible ERR_PTR()

The return value of exynos_drm_crtc_get_by_type maybe ERR_PTR(-ENODEV),
which can not be used directly. Fix this by checking the return value
before using it.

Signed-off-by: Xiang Yang <xiangyang3@huawei.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/exynos/exynos_hdmi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index dc01c188c0e09..981bffacda243 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -1849,6 +1849,8 @@ static int hdmi_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 
 	crtc = exynos_drm_crtc_get_by_type(drm_dev, EXYNOS_DISPLAY_TYPE_HDMI);
+	if (IS_ERR(crtc))
+		return PTR_ERR(crtc);
 	crtc->pipe_clk = &hdata->phy_clk;
 
 	ret = hdmi_create_connector(encoder);
-- 
2.42.0


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[PATCH AUTOSEL 5.10 16/16] drm/exynos: fix a wrong error checking

[Sasha Levin]

From: Inki Dae <inki.dae@samsung.com>

[ Upstream commit 8d1b7809684c688005706125b804e1f9792d2b1b ]

Fix a wrong error checking in exynos_drm_dma.c module.

In the exynos_drm_register_dma function, both arm_iommu_create_mapping()
and iommu_get_domain_for_dev() functions are expected to return NULL as
an error.

However, the error checking is performed using the statement
if(IS_ERR(mapping)), which doesn't provide a suitable error value.
So check if 'mapping' is NULL, and if it is, return -ENODEV.

This issue[1] was reported by Dan.

Changelog v1:
- fix build warning.

[1] https://lore.kernel.org/all/33e52277-1349-472b-a55b-ab5c3462bfcf@moroto.mountain/

Reported-by : Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/exynos/exynos_drm_dma.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dma.c b/drivers/gpu/drm/exynos/exynos_drm_dma.c
index bf33c3084cb41..6b4d6da3b1f4e 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dma.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c
@@ -108,18 +108,16 @@ int exynos_drm_register_dma(struct drm_device *drm, struct device *dev,
 		return 0;
 
 	if (!priv->mapping) {
-		void *mapping;
+		void *mapping = NULL;
 
 		if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
 			mapping = arm_iommu_create_mapping(&platform_bus_type,
 				EXYNOS_DEV_ADDR_START, EXYNOS_DEV_ADDR_SIZE);
 		else if (IS_ENABLED(CONFIG_IOMMU_DMA))
 			mapping = iommu_get_domain_for_dev(priv->dma_dev);
-		else
-			mapping = ERR_PTR(-ENODEV);
 
-		if (IS_ERR(mapping))
-			return PTR_ERR(mapping);
+		if (!mapping)
+			return -ENODEV;
 		priv->mapping = mapping;
 	}
 
-- 
2.42.0


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