| Message ID | 20221121223717.3429913-1-nfraprado@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/mediatek: Clean dangling pointer on bind error path | expand |
Il 21/11/22 23:37, Nícolas F. R. A. Prado ha scritto: > mtk_drm_bind() can fail, in which case drm_dev_put() is called, > destroying the drm_device object. However a pointer to it was still > being held in the private object, and that pointer would be passed along > to DRM in mtk_drm_sys_prepare() if a suspend were triggered at that > point, resulting in a panic. Clean the pointer when destroying the > object in the error path to prevent this from happening. > > Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> > Fixes tag please! :-) Cheers, Angelo > --- > > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > index 39a42dc8fb85..a21ff1b3258c 100644 > --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c > +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > @@ -514,6 +514,7 @@ static int mtk_drm_bind(struct device *dev) > err_deinit: > mtk_drm_kms_deinit(drm); > err_free: > + private->drm = NULL; > drm_dev_put(drm); > return ret; > }
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index 39a42dc8fb85..a21ff1b3258c 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -514,6 +514,7 @@ static int mtk_drm_bind(struct device *dev) err_deinit: mtk_drm_kms_deinit(drm); err_free: + private->drm = NULL; drm_dev_put(drm); return ret; }
mtk_drm_bind() can fail, in which case drm_dev_put() is called, destroying the drm_device object. However a pointer to it was still being held in the private object, and that pointer would be passed along to DRM in mtk_drm_sys_prepare() if a suspend were triggered at that point, resulting in a panic. Clean the pointer when destroying the object in the error path to prevent this from happening. Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com> --- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 + 1 file changed, 1 insertion(+)