From: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx>
[ Upstream commit 776e78677f514ecddd12dba48b9040958999bd5a ]
meson_drv_bind() registers a meson_drm struct as the device's privdata,
but meson_drv_unbind() tries to retrieve a drm_device. This may cause a
segfault on shutdown:
[ 5194.593429] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000197
...
[ 5194.788850] Call trace:
[ 5194.791349] drm_dev_unregister+0x1c/0x118 [drm]
[ 5194.795848] meson_drv_unbind+0x50/0x78 [meson_drm]
Retrieve the right pointer in meson_drv_unbind().
Fixes: bbbe775ec5b5 ("drm: Add support for Amlogic Meson Graphic Controller")
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx>
Acked-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190322152657.13752-1-jean-philippe.brucker@xxxxxxx
Signed-off-by: Sasha Levin (Microsoft) <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/meson/meson_drv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index 611ac340fb28..4a72fa53a1d5 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -317,8 +317,8 @@ static int meson_drv_bind(struct device *dev)
static void meson_drv_unbind(struct device *dev)
{
- struct drm_device *drm = dev_get_drvdata(dev);
- struct meson_drm *priv = drm->dev_private;
+ struct meson_drm *priv = dev_get_drvdata(dev);
+ struct drm_device *drm = priv->drm;
drm_dev_unregister(drm);
drm_kms_helper_poll_fini(drm);
--
2.19.1
