From: Pavel Skripkin paskripkin@gmail.com
commit 10eff1f5788b6ffac212c254e2f3666219576889 upstream.
This reverts commit ab609f25d19858513919369ff3d9a63c02cd9e2e.
This patch is correct in the sense that we _should_ call device_put() in case of device_register() failure, but the problem in this code is more vast.
We need to set bus->state to UNMDIOBUS_REGISTERED before calling device_register() to correctly release the device in mdiobus_free(). This patch prevents us from doing it, since in case of device_register() failure put_device() will be called 2 times and it will cause UAF or something else.
Also, Reported-by: tag in revered commit was wrong, since syzbot reported different leak in same function.
Link: https://lore.kernel.org/netdev/20210928092657.GI2048@kadam/ Acked-by: Yanfei Xu yanfei.xu@windriver.com Signed-off-by: Pavel Skripkin paskripkin@gmail.com Link: https://lore.kernel.org/r/f12fb1faa4eccf0f355788225335eb4309ff2599.163302406... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/phy/mdio_bus.c | 1 - 1 file changed, 1 deletion(-)
--- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -544,7 +544,6 @@ int __mdiobus_register(struct mii_bus *b err = device_register(&bus->dev); if (err) { pr_err("mii_bus %s failed to register\n", bus->id); - put_device(&bus->dev); return -EINVAL; }