[ 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@arm.com Acked-by: Neil Armstrong narmstrong@baylibre.com Signed-off-by: Neil Armstrong narmstrong@baylibre.com Link: https://patchwork.freedesktop.org/patch/msgid/20190322152657.13752-1-jean-ph... Signed-off-by: Sasha Levin (Microsoft) sashal@kernel.org --- 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);