[PATCH net v2 0/4] net: fix device reference leaks

This series fixes a number of device reference leaks (and one of_node
leak) due to failure to drop the references taken by bus_find_device()
and friends.

Note that the final two patches have been compile tested only.

Thanks,
Johan


v2
 - hold reference to cpsw-phy-sel device while accessing private data as
   requested by David. Also update the commit message. (patch 1/4)
 - add linux-omap on CC where appropriate


Johan Hovold (4):
  phy: fix device reference leaks
  net: ethernet: ti: cpsw: fix device and of_node leaks
  net: ethernet: ti: davinci_emac: fix device reference leak
  net: hns: fix device reference leaks

 drivers/net/ethernet/hisilicon/hns/hnae.c |  8 +++++++-
 drivers/net/ethernet/ti/cpsw-phy-sel.c    |  3 +++
 drivers/net/ethernet/ti/davinci_emac.c    | 10 ++++++----
 drivers/net/phy/phy_device.c              |  2 ++
 4 files changed, 18 insertions(+), 5 deletions(-)

-- 
2.7.3

Make sure to drop the reference taken by bus_find_device_by_name()
before returning from phy_connect() and phy_attach().

Note that both function still take a reference to the phy device
through phy_attach_direct().

Fixes: e13934563db0 ("[PATCH] PHY Layer fixup")
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/net/phy/phy_device.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index e977ba931878..1a4bf8acad78 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c

@@ -723,6 +723,7 @@ struct phy_device *phy_connect(struct net_device *dev, const char *bus_id,
 	phydev = to_phy_device(d);
 
 	rc = phy_connect_direct(dev, phydev, handler, interface);
+	put_device(d);
 	if (rc)
 		return ERR_PTR(rc);
 

@@ -953,6 +954,7 @@ struct phy_device *phy_attach(struct net_device *dev, const char *bus_id,
 	phydev = to_phy_device(d);
 
 	rc = phy_attach_direct(dev, phydev, phydev->dev_flags, interface);
+	put_device(d);
 	if (rc)
 		return ERR_PTR(rc);
 

-- 
2.7.3

Make sure to drop the references taken by bus_find_device() before
returning from emac_dev_open().

Note that phy_connect still takes a reference to the phy device.

Fixes: 5d69e0076a72 ("net: davinci_emac: switch to new mdio")
Cc: Mugunthan V N <redacted>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/net/ethernet/ti/davinci_emac.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index 2fd94a5bc1f3..84fbe5714f8b 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c

@@ -1410,6 +1410,7 @@ static int emac_dev_open(struct net_device *ndev)
 	int i = 0;
 	struct emac_priv *priv = netdev_priv(ndev);
 	struct phy_device *phydev = NULL;
+	struct device *phy = NULL;
 
 	ret = pm_runtime_get_sync(&priv->pdev->dev);
 	if (ret < 0) {

@@ -1488,19 +1489,20 @@ static int emac_dev_open(struct net_device *ndev)
 
 	/* use the first phy on the bus if pdata did not give us a phy id */
 	if (!phydev && !priv->phy_id) {
-		struct device *phy;
-
 		phy = bus_find_device(&mdio_bus_type, NULL, NULL,
 				      match_first_device);
-		if (phy)
+		if (phy) {
 			priv->phy_id = dev_name(phy);
+			if (!priv->phy_id || !*priv->phy_id)
+				put_device(phy);
+		}
 	}
 
 	if (!phydev && priv->phy_id && *priv->phy_id) {
 		phydev = phy_connect(ndev, priv->phy_id,
 				     &emac_adjust_link,
 				     PHY_INTERFACE_MODE_MII);
-
+		put_device(phy);	/* reference taken by bus_find_device */
 		if (IS_ERR(phydev)) {
 			dev_err(emac_dev, "could not connect to phy %s\n",
 				priv->phy_id);

-- 
2.7.3

Make sure to drop the references taken by of_get_child_by_name() and
bus_find_device() before returning from cpsw_phy_sel().

Note that holding a reference to the cpsw-phy-sel device does not
prevent the devres-managed private data from going away.

Fixes: 5892cd135e16 ("drivers: net: cpsw-phy-sel: Add new driver...")
Cc: Mugunthan V N <redacted>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/net/ethernet/ti/cpsw-phy-sel.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/ti/cpsw-phy-sel.c b/drivers/net/ethernet/ti/cpsw-phy-sel.c
index 054a8dd23dae..ba1e45ff6aae 100644
--- a/drivers/net/ethernet/ti/cpsw-phy-sel.c
+++ b/drivers/net/ethernet/ti/cpsw-phy-sel.c

@@ -176,9 +176,12 @@ void cpsw_phy_sel(struct device *dev, phy_interface_t phy_mode, int slave)
 	}
 
 	dev = bus_find_device(&platform_bus_type, NULL, node, match);
+	of_node_put(node);
 	priv = dev_get_drvdata(dev);
 
 	priv->cpsw_phy_sel(priv, phy_mode, slave);
+
+	put_device(dev);
 }
 EXPORT_SYMBOL_GPL(cpsw_phy_sel);
 

-- 
2.7.3

Make sure to drop the reference taken by class_find_device() in
hnae_get_handle() on errors and when later releasing the handle.

Fixes: 6fe6611ff275 ("net: add Hisilicon Network Subsystem...")
Cc: Yisen Zhuang <redacted>
Cc: Salil Mehta <redacted>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/net/ethernet/hisilicon/hns/hnae.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/hisilicon/hns/hnae.c b/drivers/net/ethernet/hisilicon/hns/hnae.c
index c54c6fac0d1d..b6ed818f78ff 100644
--- a/drivers/net/ethernet/hisilicon/hns/hnae.c
+++ b/drivers/net/ethernet/hisilicon/hns/hnae.c

@@ -332,8 +332,10 @@ struct hnae_handle *hnae_get_handle(struct device *owner_dev,
 		return ERR_PTR(-ENODEV);
 
 	handle = dev->ops->get_handle(dev, port_id);
-	if (IS_ERR(handle))
+	if (IS_ERR(handle)) {
+		put_device(&dev->cls_dev);
 		return handle;
+	}
 
 	handle->dev = dev;
 	handle->owner_dev = owner_dev;

@@ -356,6 +358,8 @@ struct hnae_handle *hnae_get_handle(struct device *owner_dev,
 	for (j = i - 1; j >= 0; j--)
 		hnae_fini_queue(handle->qs[j]);
 
+	put_device(&dev->cls_dev);
+
 	return ERR_PTR(-ENOMEM);
 }
 EXPORT_SYMBOL(hnae_get_handle);

@@ -377,6 +381,8 @@ void hnae_put_handle(struct hnae_handle *h)
 		dev->ops->put_handle(h);
 
 	module_put(dev->owner);
+
+	put_device(&dev->cls_dev);
 }
 EXPORT_SYMBOL(hnae_put_handle);
 

-- 
2.7.3

From: Johan Hovold <johan@kernel.org>
Date: Thu,  3 Nov 2016 18:40:18 +0100

This series fixes a number of device reference leaks (and one of_node
leak) due to failure to drop the references taken by bus_find_device()
and friends.

Note that the final two patches have been compile tested only.

 ...

v2
 - hold reference to cpsw-phy-sel device while accessing private data as
   requested by David. Also update the commit message. (patch 1/4)
 - add linux-omap on CC where appropriate

Series applied, thanks.

On 11/03/2016 12:40 PM, Johan Hovold wrote:

Make sure to drop the references taken by of_get_child_by_name() and
bus_find_device() before returning from cpsw_phy_sel().

Note that holding a reference to the cpsw-phy-sel device does not
prevent the devres-managed private data from going away.

Fixes: 5892cd135e16 ("drivers: net: cpsw-phy-sel: Add new driver...")
Cc: Mugunthan V N <redacted>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---

Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>

-- 
regards,
-grygorii

On Tue, Nov 08, 2016 at 05:19:29PM -0600, Grygorii Strashko wrote:

On 11/03/2016 12:40 PM, Johan Hovold wrote:

quoted

Make sure to drop the references taken by of_get_child_by_name() and
bus_find_device() before returning from cpsw_phy_sel().

Note that holding a reference to the cpsw-phy-sel device does not
prevent the devres-managed private data from going away.

Fixes: 5892cd135e16 ("drivers: net: cpsw-phy-sel: Add new driver...")
Cc: Mugunthan V N <redacted>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: linux-omap@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---

Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>

Thanks for the review. Note that David has already applied these, though.

Johan