From d6373882d0b8366081a7b6f3fd595576dd1f85b5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Exp=C3=B3sito?= <jose.exposito89@gmail.com>
Date: Sun, 16 Jan 2022 19:18:44 +0100
Subject: drm/msm/dsi: invalid parameter check in msm_dsi_phy_enable
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Git-commit: 5e761a2287234bc402ba7ef07129f5103bcd775c
Patch-mainline: v5.17-rc2
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

The function performs a check on the "phy" input parameter, however, it
is used before the check.

Initialize the "dev" variable after the sanity check to avoid a possible
NULL pointer dereference.

Fixes: 5c8290284402b ("drm/msm/dsi: Split PHY drivers to separate files")
Addresses-Coverity-ID: 1493860 ("Null pointer dereference")
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220116181844.7400-1-jose.exposito89@gmail.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/msm/dsi/phy/dsi_phy.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
index c2ed177717c7..2027b38617ab 100644
--- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
+++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
@@ -808,12 +808,14 @@ int msm_dsi_phy_enable(struct msm_dsi_phy *phy,
 			struct msm_dsi_phy_clk_request *clk_req,
 			struct msm_dsi_phy_shared_timings *shared_timings)
 {
-	struct device *dev = &phy->pdev->dev;
+	struct device *dev;
 	int ret;
 
 	if (!phy || !phy->cfg->ops.enable)
 		return -EINVAL;
 
+	dev = &phy->pdev->dev;
+
 	ret = dsi_phy_enable_resource(phy);
 	if (ret) {
 		DRM_DEV_ERROR(dev, "%s: resource enable failed, %d\n",
-- 
2.38.1