[PATCH 4.9 14/28] drm/mediatek: fix possible object reference leak

From: Greg Kroah-Hartman
Date: Thu May 09 2019 - 14:45:23 EST


[ Upstream commit 2ae2c3316fb77dcf64275d011596b60104c45426 ]

The call to of_parse_phandle 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/mediatek/mtk_hdmi.c:1521:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1509, but without a corresponding object release within this function.
drivers/gpu/drm/mediatek/mtk_hdmi.c:1524:1-7: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 1509, but without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Cc: CK Hu <ck.hu@xxxxxxxxxxxx>
Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-mediatek@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_hdmi.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index 200f75e1d6198..e7a6651ceeab1 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -1528,6 +1528,7 @@ static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
of_node_put(remote);

hdmi->ddc_adpt = of_find_i2c_adapter_by_node(i2c_np);
+ of_node_put(i2c_np);
if (!hdmi->ddc_adpt) {
dev_err(dev, "Failed to get ddc i2c adapter by node\n");
return -EINVAL;
--
2.20.1