From:   Zou Wei <zou_wei@huawei.com>
To:     <airlied@linux.ie>, <daniel@ffwll.ch>, <orsonzhai@gmail.com>,
        <baolin.wang7@gmail.com>, <zhang.lyra@gmail.com>,
        <maarten.lankhorst@linux.intel.com>, <kevin3.tang@gmail.com>,
        <maxime@cerno.tech>
CC:     <dri-devel@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
        Zou Wei <zou_wei@huawei.com>
Subject: [PATCH -next] drm/sprd: fix potential NULL dereference
Date:   Tue, 14 Dec 2021 17:11:48 +0800
Message-ID: <1639473108-18629-1-git-send-email-zou_wei@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

platform_get_resource() may fail and return NULL, so we should
better check it's return value to avoid a NULL pointer dereference
a bit later in the code.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
---
 drivers/gpu/drm/sprd/sprd_dpu.c | 2 ++
 drivers/gpu/drm/sprd/sprd_dsi.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/sprd/sprd_dpu.c b/drivers/gpu/drm/sprd/sprd_dpu.c
index 06a3414..920cb7d 100644
--- a/drivers/gpu/drm/sprd/sprd_dpu.c
+++ b/drivers/gpu/drm/sprd/sprd_dpu.c
@@ -790,6 +790,8 @@ static int sprd_dpu_context_init(struct sprd_dpu *dpu,
 	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
 	ctx->base = devm_ioremap(dev, res->start, resource_size(res));
 	if (!ctx->base) {
 		dev_err(dev, "failed to map dpu registers\n");
diff --git a/drivers/gpu/drm/sprd/sprd_dsi.c b/drivers/gpu/drm/sprd/sprd_dsi.c
index 911b3cd..c90a950 100644
--- a/drivers/gpu/drm/sprd/sprd_dsi.c
+++ b/drivers/gpu/drm/sprd/sprd_dsi.c
@@ -907,6 +907,8 @@ static int sprd_dsi_context_init(struct sprd_dsi *dsi,
 	struct resource *res;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
 	ctx->base = devm_ioremap(dev, res->start, resource_size(res));
 	if (!ctx->base) {
 		drm_err(dsi->drm, "failed to map dsi host registers\n");
-- 
2.6.2