From 73bf1c9ae6c054c53b8e84452c5e46f86dd28246 Mon Sep 17 00:00:00 2001 From: Xiang Yang Date: Sat, 12 Aug 2023 14:27:48 +0800 Subject: [PATCH 1/2] drm/exynos: fix a potential error pointer dereference 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 Signed-off-by: Inki Dae --- 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 f3aaa4ea3e68..dd9903eab563 100644 --- a/drivers/gpu/drm/exynos/exynos_hdmi.c +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c @@ -1861,6 +1861,8 @@ 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); From 8d1b7809684c688005706125b804e1f9792d2b1b Mon Sep 17 00:00:00 2001 From: Inki Dae Date: Wed, 1 Nov 2023 18:36:51 +0900 Subject: [PATCH 2/2] drm/exynos: fix a wrong error checking 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 Signed-off-by: Inki Dae --- 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 a971590b8132..e2c7373f20c6 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dma.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c @@ -107,18 +107,16 @@ 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; }