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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Chen Ni <nichen@iscas.ac.cn>,
	Thierry Reding <treding@nvidia.com>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 156/317] drm/tegra: dsi: Add missing check for of_find_device_by_node
Date: Sun, 24 Mar 2024 19:32:16 -0400
Message-ID: <20240324233458.1352854-157-sashal@kernel.org>
In-Reply-To: <20240324233458.1352854-1-sashal@kernel.org>
References: <20240324233458.1352854-1-sashal@kernel.org>
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From: Chen Ni <nichen@iscas.ac.cn>

[ Upstream commit afe6fcb9775882230cd29b529203eabd5d2a638d ]

Add check for the return value of of_find_device_by_node() and return
the error if it fails in order to avoid NULL pointer dereference.

Fixes: e94236cde4d5 ("drm/tegra: dsi: Add ganged mode support")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231024080738.825553-1-nichen@iscas.ac.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/tegra/dsi.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
index de1333dc0d867..0adce882f157b 100644
--- a/drivers/gpu/drm/tegra/dsi.c
+++ b/drivers/gpu/drm/tegra/dsi.c
@@ -1534,9 +1534,11 @@ static int tegra_dsi_ganged_probe(struct tegra_dsi *dsi)
 	np = of_parse_phandle(dsi->dev->of_node, "nvidia,ganged-mode", 0);
 	if (np) {
 		struct platform_device *gangster = of_find_device_by_node(np);
+		of_node_put(np);
+		if (!gangster)
+			return -EPROBE_DEFER;
 
 		dsi->slave = platform_get_drvdata(gangster);
-		of_node_put(np);
 
 		if (!dsi->slave) {
 			put_device(&gangster->dev);
-- 
2.43.0