[PATCH AUTOSEL 4.19 7/7] drm/exynos: fix a potential error pointer dereference

[Sasha Levin]

From: Xiang Yang <xiangyang3@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Signed-off-by: Inki Dae <inki.dae@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 2092a650df7d5..551a97e45d973 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -1840,6 +1840,8 @@ 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