[PATCH 5.16 080/227] drm/atomic: Dont pollute crtc_state->mode_blob with error pointers

Greg Kroah-Hartman
2022-02-21T09:58:44Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

commit 439cf34c8e0a8a33d8c15a31be1b7423426bc765 upstream.

Make sure we don't assign an error pointer to crtc_state->mode_blob
as that will break all kinds of places that assume either NULL or a
valid pointer (eg. drm_property_blob_put()).

Cc: stable@vger.kernel.org
Reported-by: fuyufan <fuyufan@huawei.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220209091928.14766-1-ville.syrjala@linux.intel.com
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/drm_atomic_uapi.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -76,15 +76,17 @@ int drm_atomic_set_mode_for_crtc(struct
state->mode_blob = NULL;

if (mode) {
+ struct drm_property_blob *blob;
+
drm_mode_convert_to_umode(&umode, mode);
- state->mode_blob =
- drm_property_create_blob(state->crtc->dev,
- sizeof(umode),
- &umode);
- if (IS_ERR(state->mode_blob))
- return PTR_ERR(state->mode_blob);
+ blob = drm_property_create_blob(crtc->dev,
+ sizeof(umode), &umode);
+ if (IS_ERR(blob))
+ return PTR_ERR(blob);

drm_mode_copy(&state->mode, mode);
+
+ state->mode_blob = blob;
state->enable = true;
drm_dbg_atomic(crtc->dev,
"Set [MODE:%s] for [CRTC:%d:%s] state %p\n",