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

Hi,

On 17/06/2021 09:07, Jiajun Cao wrote:

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 jjcao20@fudan.edu.cn Signed-off-by: Xin Tan tanxin.ctf@gmail.com

---

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;

Please move struct drm_device before the if like :

struct meson_drm *priv = dev_get_drvdata(dev); struct drm_device *drm;

if (!priv) return; drm = priv->drm;

if (priv->canvas) {

Thanks, Neil