Date:   Sat, 11 Feb 2023 16:39:50 +0530
From:   Deepak R Varma <drv@mailo.com>
To:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
Cc:     Saurabh Singh Sengar <ssengar@microsoft.com>,
        Praveen Kumar <kumarpraveen@linux.microsoft.com>,
        Deepak R Varma <drv@mailo.com>
Subject: [PATCH] media: platform: mtk-mdp3: release node reference before
 returning
Message-ID: <Y+d3fqRG1OoYKpLB@ubun2204.myguest.virtualbox.org>
MIME-Version: 1.0
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The iterator for_each_child_of_node() increments the refcount of the
child node it is processing. Release such a reference when the loop
needs to break due to an error during its execution.
Issue identified using for_each_child.cocci Coccinelle semantic patch.

Signed-off-by: Deepak R Varma <drv@mailo.com>
---
Please note: The proposed change is compile tested only. I do not have the
necessary hardware to perform additional testing. Please suggest if there is an
alternate means available to further test this change.


 .../media/platform/mediatek/mdp3/mtk-mdp3-comp.c  | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
index 7bc05f42a23c..2c50a73bbf23 100644
--- a/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
+++ b/drivers/media/platform/mediatek/mdp3/mtk-mdp3-comp.c
@@ -898,6 +898,7 @@ static int mdp_comp_sub_create(struct mdp_dev *mdp)
 {
 	struct device *dev = &mdp->pdev->dev;
 	struct device_node *node, *parent;
+	int ret = 0;
 
 	parent = dev->of_node->parent;
 
@@ -923,16 +924,22 @@ static int mdp_comp_sub_create(struct mdp_dev *mdp)
 			dev_err(dev,
 				"Fail to get sub comp. id: type %d alias %d\n",
 				type, alias_id);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto err_free_node;
 		}
 		mdp_comp_alias_id[type]++;
 
 		comp = mdp_comp_create(mdp, node, id);
-		if (IS_ERR(comp))
-			return PTR_ERR(comp);
+		if (IS_ERR(comp)) {
+			ret = PTR_ERR(comp);
+			goto err_free_node;
+		}
 	}
+	return ret;
 
-	return 0;
+err_free_node:
+	of_node_put(node);
+	return ret;
 }
 
 void mdp_comp_destroy(struct mdp_dev *mdp)
-- 
2.34.1