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

Subsystems: mediatek switch driver, networking drivers, networking [dsa], the rest

STALE2191d

2 messages, 2 authors, 2020-08-25 · open the first message on its own page

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

From: Sumera Priyadarsini <hidden>
Date: 2020-08-24 20:03:19

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 <redacted>
---
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

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

From: David Miller <davem@davemloft.net>
Date: 2020-08-25 14:48:50

From: Sumera Priyadarsini <redacted>
Date: Tue, 25 Aug 2020 01:33:11 +0530
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 <redacted>
Applied, thank you.
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