drm/msm/dsi: invalid parameter check in msm_dsi_phy_enable

BugLink: https://bugs.launchpad.net/bugs/1959879
commit 5e761a2287234bc402ba7ef07129f5103bcd775c upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
index 8c65ef6968caf50a81565f3f9dfe8fd6fbb7d8ed..a878b8b079c6456edd126dba6b889f91f470383c 100644 (file)
--- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
+++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
@@ -806,12 +806,14 @@ 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",