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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, Liang He <windhl@126.com>,
        Helge Deller <deller@gmx.de>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 167/287] video: fbdev: amba-clcd: Fix refcount leak bugs
Date:   Tue, 23 Aug 2022 10:25:36 +0200
Message-Id: <20220823080106.383986922@linuxfoundation.org>
In-Reply-To: <20220823080100.268827165@linuxfoundation.org>
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From: Liang He <windhl@126.com>

[ Upstream commit 26c2b7d9fac42eb8317f3ceefa4c1a9a9170ca69 ]

In clcdfb_of_init_display(), we should call of_node_put() for the
references returned by of_graph_get_next_endpoint() and
of_graph_get_remote_port_parent() which have increased the refcount.

Besides, we should call of_node_put() both in fail path or when
the references are not used anymore.

Fixes: d10715be03bd ("video: ARM CLCD: Add DT support")
Signed-off-by: Liang He <windhl@126.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/fbdev/amba-clcd.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/video/fbdev/amba-clcd.c b/drivers/video/fbdev/amba-clcd.c
index 549f78e77255..81f64ef6fa4c 100644
--- a/drivers/video/fbdev/amba-clcd.c
+++ b/drivers/video/fbdev/amba-clcd.c
@@ -772,8 +772,10 @@ static int clcdfb_of_init_display(struct clcd_fb *fb)
 		return -ENODEV;
 
 	panel = of_graph_get_remote_port_parent(endpoint);
-	if (!panel)
-		return -ENODEV;
+	if (!panel) {
+		err = -ENODEV;
+		goto out_endpoint_put;
+	}
 
 	if (fb->vendor->init_panel) {
 		err = fb->vendor->init_panel(fb, panel);
@@ -783,11 +785,11 @@ static int clcdfb_of_init_display(struct clcd_fb *fb)
 
 	err = clcdfb_of_get_backlight(panel, fb->panel);
 	if (err)
-		return err;
+		goto out_panel_put;
 
 	err = clcdfb_of_get_mode(&fb->dev->dev, panel, fb->panel);
 	if (err)
-		return err;
+		goto out_panel_put;
 
 	err = of_property_read_u32(fb->dev->dev.of_node, "max-memory-bandwidth",
 			&max_bandwidth);
@@ -816,11 +818,21 @@ static int clcdfb_of_init_display(struct clcd_fb *fb)
 
 	if (of_property_read_u32_array(endpoint,
 			"arm,pl11x,tft-r0g0b0-pads",
-			tft_r0b0g0, ARRAY_SIZE(tft_r0b0g0)) != 0)
-		return -ENOENT;
+			tft_r0b0g0, ARRAY_SIZE(tft_r0b0g0)) != 0) {
+		err = -ENOENT;
+		goto out_panel_put;
+	}
+
+	of_node_put(panel);
+	of_node_put(endpoint);
 
 	return clcdfb_of_init_tft_panel(fb, tft_r0b0g0[0],
 					tft_r0b0g0[1],  tft_r0b0g0[2]);
+out_panel_put:
+	of_node_put(panel);
+out_endpoint_put:
+	of_node_put(endpoint);
+	return err;
 }
 
 static int clcdfb_of_vram_setup(struct clcd_fb *fb)
-- 
2.35.1