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Message-Id: <20250717022309.3339976-2-make24@iscas.ac.cn>
Date: Thu, 17 Jul 2025 10:23:08 +0800
From: Ma Ke <make24@...as.ac.cn>
To: ioana.ciornei@....com,
davem@...emloft.net,
andrew+netdev@...n.ch,
edumazet@...gle.com,
kuba@...nel.org,
pabeni@...hat.com,
horms@...nel.org
Cc: netdev@...r.kernel.org,
linux-kernel@...r.kernel.org,
akpm@...ux-foundation.org,
Ma Ke <make24@...as.ac.cn>,
stable@...r.kernel.org
Subject: [PATCH net v2 2/3] dpaa2-eth: Fix device reference count leak in MAC endpoint handling
The fsl_mc_get_endpoint() function uses device_find_child() for
localization, which implicitly calls get_device() to increment the
device's reference count before returning the pointer. However, the
caller dpaa2_eth_connect_mac() fails to properly release this
reference in multiple scenarios. We should call put_device() to
decrement reference count properly.
As comment of device_find_child() says, 'NOTE: you will need to drop
the reference with put_device() after use'.
Found by code review.
Cc: stable@...r.kernel.org
Fixes: 719479230893 ("dpaa2-eth: add MAC/PHY support through phylink")
Signed-off-by: Ma Ke <make24@...as.ac.cn>
---
drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index b82f121cadad..0f4efd505332 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -4666,12 +4666,19 @@ static int dpaa2_eth_connect_mac(struct dpaa2_eth_priv *priv)
return PTR_ERR(dpmac_dev);
}
- if (IS_ERR(dpmac_dev) || dpmac_dev->dev.type != &fsl_mc_bus_dpmac_type)
+ if (IS_ERR(dpmac_dev))
return 0;
+ if (dpmac_dev->dev.type != &fsl_mc_bus_dpmac_type) {
+ err = 0;
+ goto out_put_device;
+ }
+
mac = kzalloc(sizeof(struct dpaa2_mac), GFP_KERNEL);
- if (!mac)
- return -ENOMEM;
+ if (!mac) {
+ err = -ENOMEM;
+ goto out_put_device;
+ }
mac->mc_dev = dpmac_dev;
mac->mc_io = priv->mc_io;
@@ -4705,6 +4712,8 @@ static int dpaa2_eth_connect_mac(struct dpaa2_eth_priv *priv)
dpaa2_mac_close(mac);
err_free_mac:
kfree(mac);
+out_put_device:
+ put_device(&dpmac_dev->dev);
return err;
}
--
2.25.1
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