[PATCH v2] drm/meson: fix potential NULL pointer exception in meson_drv_unbind()
Jiajun Cao
jjcao20 at fudan.edu.cn
Thu Jun 17 22:28:00 PDT 2021
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 at fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf at gmail.com>
---
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
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