[PATCH 4.19 185/276] drm/pl111: fix possible object reference leak

From: Greg Kroah-Hartman
Date: Thu May 30 2019 - 00:09:40 EST


[ Upstream commit bc29d3a69d4c1bd1a103e8b3c1ed81b807c1870b ]

The call to of_find_matching_node_and_match returns a node pointer with
refcount incremented thus it must be explicitly decremented after the
last usage.

Detected by coccinelle with the following warnings:
drivers/gpu/drm/pl111/pl111_versatile.c:333:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 317, but without a corresponding object release within this function.
drivers/gpu/drm/pl111/pl111_versatile.c:340:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 317, but without a corresponding object release within this function.
drivers/gpu/drm/pl111/pl111_versatile.c:346:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 317, but without a corresponding object release within this function.
drivers/gpu/drm/pl111/pl111_versatile.c:354:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 317, but without a corresponding object release within this function.
drivers/gpu/drm/pl111/pl111_versatile.c:395:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 317, but without a corresponding object release within this function.
drivers/gpu/drm/pl111/pl111_versatile.c:402:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 317, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Cc: Eric Anholt <eric@xxxxxxxxxx> (supporter:DRM DRIVER FOR ARM PL111 CLCD)
Cc: David Airlie <airlied@xxxxxxxx> (maintainer:DRM DRIVERS)
Cc: Daniel Vetter <daniel@xxxxxxxx> (maintainer:DRM DRIVERS)
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx (open list:DRM DRIVERS)
Cc: linux-kernel@xxxxxxxxxxxxxxx (open list)
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/1554307455-40361-6-git-send-email-wen.yang99@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/pl111/pl111_versatile.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/pl111/pl111_versatile.c b/drivers/gpu/drm/pl111/pl111_versatile.c
index b9baefdba38a1..1c318ad32a8cd 100644
--- a/drivers/gpu/drm/pl111/pl111_versatile.c
+++ b/drivers/gpu/drm/pl111/pl111_versatile.c
@@ -330,6 +330,7 @@ int pl111_versatile_init(struct device *dev, struct pl111_drm_dev_private *priv)
ret = vexpress_muxfpga_init();
if (ret) {
dev_err(dev, "unable to initialize muxfpga driver\n");
+ of_node_put(np);
return ret;
}

@@ -337,17 +338,20 @@ int pl111_versatile_init(struct device *dev, struct pl111_drm_dev_private *priv)
pdev = of_find_device_by_node(np);
if (!pdev) {
dev_err(dev, "can't find the sysreg device, deferring\n");
+ of_node_put(np);
return -EPROBE_DEFER;
}
map = dev_get_drvdata(&pdev->dev);
if (!map) {
dev_err(dev, "sysreg has not yet probed\n");
platform_device_put(pdev);
+ of_node_put(np);
return -EPROBE_DEFER;
}
} else {
map = syscon_node_to_regmap(np);
}
+ of_node_put(np);

if (IS_ERR(map)) {
dev_err(dev, "no Versatile syscon regmap\n");
--
2.20.1