[PATCH v2] drm/meson: fix potential NULL pointer exception in meson_drv_unbind()

[Jiajun Cao]

Fix a potential NULL pointer exception when meson_drv_unbind()
attempts to operate on the driver_data priv which may be NULL.
Add a null pointer check on the priv struct to avoid the NULL
pointer dereference after calling dev_get_drvdata(), just like
the null pointer checks done on the struct priv in the function
meson_drv_shutdown(), meson_drv_pm_suspend() and meson_drv_pm_resume().

Signed-off-by: Jiajun Cao 
Signed-off-by: Xin Tan 
---
 drivers/gpu/drm/meson/meson_drv.c | 6 +-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/meson/meson_drv.c 
b/drivers/gpu/drm/meson/meson_drv.c
index 07fcd12dca16..f544fba8c44e 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -380,7 +380,10 @@ static int meson_drv_bind(struct device *dev)
 static void meson_drv_unbind(struct device *dev)
 {
struct meson_drm *priv = dev_get_drvdata(dev);
-   struct drm_device *drm = priv->drm;
+   struct drm_device *drm;
+
+   if (!priv)
+   return;
 
if (priv->canvas) {
meson_canvas_free(priv->canvas, priv->canvas_id_osd1);
@@ -389,6 +392,7 @@ static void meson_drv_unbind(struct device *dev)
meson_canvas_free(priv->canvas, priv->canvas_id_vd1_2);
}
 
+   drm = priv->drm;
drm_dev_unregister(drm);
drm_kms_helper_poll_fini(drm);
drm_atomic_helper_shutdown(drm);
-- 
2.17.1

[PATCH] drm/meson: fix potential NULL pointer exception in meson_drv_unbind()

[Jiajun Cao]

Fix a potential NULL pointer exception when meson_drv_unbind()
attempts to operate on the driver_data priv which may be NULL.
Add a null pointer check on the priv struct to avoid the NULL
pointer dereference after calling dev_get_drvdata(), just like
the null pointer checks done on the struct priv in the function
meson_drv_shutdown(), meson_drv_pm_suspend() and meson_drv_pm_resume().

Signed-off-by: Jiajun Cao 
Signed-off-by: Xin Tan 
---
 drivers/gpu/drm/meson/meson_drv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/meson/meson_drv.c 
b/drivers/gpu/drm/meson/meson_drv.c
index 07fcd12dca16..adea6a2b28f5 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -380,6 +380,8 @@ static int meson_drv_bind(struct device *dev)
 static void meson_drv_unbind(struct device *dev)
 {
struct meson_drm *priv = dev_get_drvdata(dev);
+   if (!priv)
+   return;
struct drm_device *drm = priv->drm;
 
if (priv->canvas) {
-- 
2.17.1