[PATCH 5.14 127/151] drm/msm: Fix null pointer dereference on pointer edp

Greg Kroah-Hartman
2021-10-18T14:00:41Z

From: Colin Ian King <colin.king@canonical.com>

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: ab5b0107ccf3 ("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>
---
drivers/gpu/drm/msm/edp/edp_ctrl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/msm/edp/edp_ctrl.c
+++ b/drivers/gpu/drm/msm/edp/edp_ctrl.c
@@ -1116,7 +1116,7 @@ void msm_edp_ctrl_power(struct edp_ctrl
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) {
@@ -1124,6 +1124,7 @@ int msm_edp_ctrl_init(struct msm_edp *ed
return -EINVAL;
}

+ dev = &edp->pdev->dev;
ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
if (!ctrl)
return -ENOMEM;