[PATCH] drm/msm/dsi: Fix potential NULL pointer dereference in msm_dsi_modeset_init

From: Gustavo A. R. Silva
Date: Fri Feb 02 2018 - 08:05:24 EST


_dev_ is being dereferenced before it is null checked, hence there
is a potential null pointer dereference.

Fix this by moving the pointer dereference after _dev_ has been
null checked.

Fixes: d4e7f38d70ef ("drm/msm/dsi: check msm_dsi and dsi pointers before use")
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dsi/dsi.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c
index ee7e090..b744bcc 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.c
+++ b/drivers/gpu/drm/msm/dsi/dsi.c
@@ -192,13 +192,14 @@ void __exit msm_dsi_unregister(void)
int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
struct drm_encoder *encoder)
{
- struct msm_drm_private *priv = dev->dev_private;
+ struct msm_drm_private *priv;
struct drm_bridge *ext_bridge;
int ret;

if (WARN_ON(!encoder) || WARN_ON(!msm_dsi) || WARN_ON(!dev))
return -EINVAL;

+ priv = dev->dev_private;
msm_dsi->dev = dev;

ret = msm_dsi_host_modeset_init(msm_dsi->host, dev);
--
2.7.4