This is a note to let you know that I've just added the patch titled
net: mdio: fix unbalanced fwnode reference count in mdio_device_release()
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-mdio-fix-unbalanced-fwnode-reference-count-in-md.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit cd783c3b86050e821d753825cf51668528183c2d
Author: Zeng Heng <zengheng4@xxxxxxxxxx>
Date: Sat Dec 3 15:34:41 2022 +0800
net: mdio: fix unbalanced fwnode reference count in mdio_device_release()
[ Upstream commit cb37617687f2bfa5b675df7779f869147c9002bd ]
There is warning report about of_node refcount leak
while probing mdio device:
OF: ERROR: memory leak, expected refcount 1 instead of 2,
of_node_get()/of_node_put() unbalanced - destroy cset entry:
attach overlay node /spi/soc@0/mdio@710700c0/ethernet@4
In of_mdiobus_register_device(), we increase fwnode refcount
by fwnode_handle_get() before associating the of_node with
mdio device, but it has never been decreased in normal path.
Since that, in mdio_device_release(), it needs to call
fwnode_handle_put() in addition instead of calling kfree()
directly.
After above, just calling mdio_device_free() in the error handle
path of of_mdiobus_register_device() is enough to keep the
refcount balanced.
Fixes: a9049e0c513c ("mdio: Add support for mdio drivers.")
Signed-off-by: Zeng Heng <zengheng4@xxxxxxxxxx>
Reviewed-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
Reviewed-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221203073441.3885317-1-zengheng4@xxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/mdio/of_mdio.c b/drivers/net/mdio/of_mdio.c
index 796e9c7857d0..510822d6d0d9 100644
--- a/drivers/net/mdio/of_mdio.c
+++ b/drivers/net/mdio/of_mdio.c
@@ -68,8 +68,9 @@ static int of_mdiobus_register_device(struct mii_bus *mdio,
/* All data is now stored in the mdiodev struct; register it. */
rc = mdio_device_register(mdiodev);
if (rc) {
+ device_set_node(&mdiodev->dev, NULL);
+ fwnode_handle_put(fwnode);
mdio_device_free(mdiodev);
- of_node_put(child);
return rc;
}
diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index 250742ffdfd9..044828d081d2 100644
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
@@ -21,6 +21,7 @@
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/unistd.h>
+#include <linux/property.h>
void mdio_device_free(struct mdio_device *mdiodev)
{
@@ -30,6 +31,7 @@ EXPORT_SYMBOL(mdio_device_free);
static void mdio_device_release(struct device *dev)
{
+ fwnode_handle_put(dev->fwnode);
kfree(to_mdio_device(dev));
}
