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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Zeng Jingxiang <linuszeng@tencent.com>,
        Robert Foss <robert.foss@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 447/530] gpu: lontium-lt9611: Fix NULL pointer dereference in lt9611_connector_init()
Date:   Mon, 24 Oct 2022 13:33:11 +0200
Message-Id: <20221024113105.273274733@linuxfoundation.org>
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From: Zeng Jingxiang <linuszeng@tencent.com>

[ Upstream commit ef8886f321c5dab8124b9153d25afa2a71d05323 ]

A NULL check for bridge->encoder shows that it may be NULL, but it
already been dereferenced on all paths leading to the check.
812	if (!bridge->encoder) {

Dereference the pointer bridge->encoder.
810	drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);

Signed-off-by: Zeng Jingxiang <linuszeng@tencent.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220727073119.1578972-1-zengjx95@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/bridge/lontium-lt9611.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
index 29b1ce2140ab..1dcc28a4d853 100644
--- a/drivers/gpu/drm/bridge/lontium-lt9611.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
@@ -816,13 +816,14 @@ static int lt9611_connector_init(struct drm_bridge *bridge, struct lt9611 *lt961
 
 	drm_connector_helper_add(&lt9611->connector,
 				 &lt9611_bridge_connector_helper_funcs);
-	drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);
 
 	if (!bridge->encoder) {
 		DRM_ERROR("Parent encoder object not found");
 		return -ENODEV;
 	}
 
+	drm_connector_attach_encoder(&lt9611->connector, bridge->encoder);
+
 	return 0;
 }
 
-- 
2.35.1