linux-kernel - [PATCH AUTOSEL 5.4 12/12] drm/exynos: fix a wrong error checking

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20231211140219.392379-12-sashal@kernel.org>
Date:   Mon, 11 Dec 2023 09:02:05 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Inki Dae <inki.dae@...sung.com>, Sasha Levin <sashal@...nel.org>,
        sw0312.kim@...sung.com, kyungmin.park@...sung.com,
        airlied@...il.com, daniel@...ll.ch, krzysztof.kozlowski@...aro.org,
        dri-devel@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 12/12] drm/exynos: fix a wrong error checking

From: Inki Dae <inki.dae@...sung.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@...aro.org>
Signed-off-by: Inki Dae <inki.dae@...sung.com>
Signed-off-by: Sasha Levin <sashal@...nel.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 a3c9d8b9e1a18..e07d31b9a921a 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dma.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c
@@ -133,18 +133,16 @@ 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