drm/msm: Fix null pointer dereference on pointer edp

commit 2133c4fc8e1348dcb752f267a143fe2254613b34 upstream.

The initialization of pointer dev dereferences pointer edp before
edp is null checked, so there is a potential null pointer deference
issue. Fix this by only dereferencing edp after edp has been null
checked.

Addresses-Coverity: ("Dereference before null check")
Fixes: 777b6cb95893 ("drm/msm: Initial add eDP support in msm drm driver (v5)")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20210929121857.213922-1-colin.king@canonical.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/msm/edp/edp_ctrl.c b/drivers/gpu/drm/msm/edp/edp_ctrl.c
index 7f3dd3ffe2c9bb1ddf03db33d55e91ea54f121f8..bbbd96f9eaa06596fd5ae5de86238419bb8f73de 100644 (file)
--- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
+++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
@@ -1082,7 +1082,7 @@ void msm_edp_ctrl_power(struct edp_ctrl *ctrl, bool on)
 int msm_edp_ctrl_init(struct msm_edp *edp)
 {
        struct edp_ctrl *ctrl = NULL;
-       struct device *dev = &edp->pdev->dev;
+       struct device *dev;
        int ret;
 
        if (!edp) {
@@ -1090,6 +1090,7 @@ int msm_edp_ctrl_init(struct msm_edp *edp)
                return -EINVAL;
        }
 
+       dev = &edp->pdev->dev;
        ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
        if (!ctrl)
                return -ENOMEM;