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From:   Fedor Pchelkin <pchelkin@ispras.ru>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org
Cc:     Fedor Pchelkin <pchelkin@ispras.ru>, fuyufan <fuyufan@huawei.com>,
        =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= 
        <ville.syrjala@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Alexey Khoroshilov <khoroshilov@ispras.ru>,
        lvc-project@linuxtesting.org, Maxime Ripard <maxime@cerno.tech>
Subject: [PATCH 5.4/5.10 1/1] drm/atomic: Don't pollute crtc_state->mode_blob with error pointers
Date:   Thu,  1 Jun 2023 17:40:16 +0300
Message-Id: <20230601144016.475176-2-pchelkin@ispras.ru>
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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: Fedor Pchelkin <pchelkin@ispras.ru>
---
 drivers/gpu/drm/drm_atomic_uapi.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 25c269bc4681..b6062833370f 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -75,15 +75,17 @@ int drm_atomic_set_mode_for_crtc(struct drm_crtc_state *state,
 	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_DEBUG_ATOMIC("Set [MODE:%s] for [CRTC:%d:%s] state %p\n",
 				 mode->name, crtc->base.id, crtc->name, state);
-- 
2.34.1