[PATCH V4] net: dsa: mt7530: Add of_node_put() before break and return statements

From: Sumera Priyadarsini <sylphrenadin@gmail.com>
To: davem@davemloft.net
Cc: andrew@lunn.ch, f.fainelli@gmail.com, netdev@vger.kernel.org,
	sean.wang@mediatek.com, linux-kernel@vger.kernel.org,
	Julia.Lawall@lip6.fr, linux-mediatek@lists.infradead.org,
	matthias.bgg@gmail.com, kuba@kernel.org,
	vivien.didelot@gmail.com, linux-arm-kernel@lists.infradead.org
Subject: [PATCH V4] net: dsa: mt7530: Add of_node_put() before break and return statements
Date: Tue, 25 Aug 2020 01:33:11 +0530	[thread overview]
Message-ID: <20200824200311.GA19436@Kaladin> (raw)

Every iteration of for_each_child_of_node() decrements
the reference count of the previous node, however when control
is transferred from the middle of the loop, as in the case of
a return or break or goto, there is no decrement thus ultimately
resulting in a memory leak.

Fix a potential memory leak in mt7530.c by inserting of_node_put()
before the break and return statements.

Issue found with Coccinelle.

Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
---
Changes in v2:
        Add another of_node_put() in for_each_child_of_node() as
pointed out by Andrew.

Changes in v3:
        - Correct syntax errors
        - Modify commit message

Changes in v4:
	- Change commit prefix to include the driver name,
mt7530, as pointed out by Vladimir.
	- Change the signoff to the correct format.

---
 drivers/net/dsa/mt7530.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 8dcb8a49ab67..4b4701c69fe1 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -1326,14 +1326,17 @@ mt7530_setup(struct dsa_switch *ds)
 
 			if (phy_node->parent == priv->dev->of_node->parent) {
 				ret = of_get_phy_mode(mac_np, &interface);
-				if (ret && ret != -ENODEV)
+				if (ret && ret != -ENODEV) {
+					of_node_put(mac_np);
 					return ret;
+				}
 				id = of_mdio_parse_addr(ds->dev, phy_node);
 				if (id == 0)
 					priv->p5_intf_sel = P5_INTF_SEL_PHY_P0;
 				if (id == 4)
 					priv->p5_intf_sel = P5_INTF_SEL_PHY_P4;
 			}
+			of_node_put(mac_np);
 			of_node_put(phy_node);
 			break;
 		}
-- 
2.17.1


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