Re: [PATCH] net: mdiobus: Fix memory leak in __mdiobus_register

From: Pavel Skripkin
Date: Tue Sep 28 2021 - 06:47:03 EST

On 9/28/21 13:39, Dan Carpenter wrote:
No, the syzbot link was correct.

Link is correct, but Yanfei's patch does not fix this bug. Syzbot reported leak, that you described below, not the Yanfei one.

You gave me that link again but I think you must be complaining about
a different bug which involves mdiobus_free(). Your bug is something
like this:

838 err = mdiobus_register(priv->mii_bus);
839 if (err) {
840 mdiobus_free(priv->mii_bus);

This error path will leak.

841 pr_err("mdio bus registration failed\n");
842 return err;
843 }

Your patch is more complicated than necessary... Just do:

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index ee8313a4ac71..c380a30a77bc 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -538,6 +538,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
bus->dev.groups = NULL;
dev_set_name(&bus->dev, "%s", bus->id);
err = device_register(&bus->dev);
if (err) {
pr_err("mii_bus %s failed to register\n", bus->id);

yep, it's the same as mine, but I thought, that MDIOBUS_UNREGISTERED is not correct name for this state :) Anyway, thank you for suggestion

With regards,
Pavel Skripkin