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| author | Pavel Skripkin <paskripkin@gmail.com> | 2021-09-30 20:50:28 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-10-01 03:11:59 +0300 |
| commit | ca6e11c337daf7925ff8a2aac8e84490a8691905 (patch) | |
| tree | 29443de2880c9ebb8ff7028e883238c3ace48ab2 | |
| parent | 10eff1f5788b6ffac212c254e2f3666219576889 (diff) | |
| download | linux-ca6e11c337daf7925ff8a2aac8e84490a8691905.tar.xz | |
phy: mdio: fix memory leak
Syzbot reported memory leak in MDIO bus interface, the problem was in
wrong state logic.
MDIOBUS_ALLOCATED indicates 2 states:
1. Bus is only allocated
2. Bus allocated and __mdiobus_register() fails, but
device_register() was called
In case of device_register() has been called we should call put_device()
to correctly free the memory allocated for this device, but mdiobus_free()
calls just kfree(dev) in case of MDIOBUS_ALLOCATED state
To avoid this behaviour we need to set bus->state to MDIOBUS_UNREGISTERED
_before_ calling device_register(), because put_device() should be
called even in case of device_register() failure.
Link: https://lore.kernel.org/netdev/YVMRWNDZDUOvQjHL@shell.armlinux.org.uk/
Fixes: 46abc02175b3 ("phylib: give mdio buses a device tree presence")
Reported-and-tested-by: syzbot+398e7dc692ddbbb4cfec@syzkaller.appspotmail.com
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/eceae1429fbf8fa5c73dd2a0d39d525aa905074d.1633024062.git.paskripkin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/phy/mdio_bus.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 53f034fc2ef7..fca8e335d750 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -534,6 +534,13 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) bus->dev.groups = NULL; dev_set_name(&bus->dev, "%s", bus->id); + /* We need to set state to MDIOBUS_UNREGISTERED to correctly release + * the device in mdiobus_free() + * + * State will be updated later in this function in case of success + */ + bus->state = MDIOBUS_UNREGISTERED; + err = device_register(&bus->dev); if (err) { pr_err("mii_bus %s failed to register\n", bus->id); |