[PATCH 5.18 0912/1095] video: fbdev: amba-clcd: Fix refcount leak bugs

From: Greg Kroah-Hartman
Date: Mon Aug 15 2022 - 18:50:20 EST


From: Liang He <windhl@xxxxxxx>

[ 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@xxxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 8080116aea84..f65c96d1394d 100644
--- a/drivers/video/fbdev/amba-clcd.c
+++ b/drivers/video/fbdev/amba-clcd.c
@@ -698,16 +698,18 @@ 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;
+ }

err = clcdfb_of_get_backlight(&fb->dev->dev, 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);
@@ -736,11 +738,21 @@ 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