On Tue, Dec 13, 2022 at 08:56:14PM +0800, Li Zetao wrote:
> There is a memory leaks reported by kmemleak:
>
> unreferenced object 0xffff888116111000 (size 2048):
> comm "modprobe", pid 817, jiffies 4294759745 (age 76.502s)
> hex dump (first 32 bytes):
> 00 c4 0a 04 81 88 ff ff 08 10 11 16 81 88 ff ff ................
> 08 10 11 16 81 88 ff ff 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<ffffffff815bcd82>] kmalloc_trace+0x22/0x60
> [<ffffffff827e20ee>] phy_device_create+0x4e/0x90
> [<ffffffff827e6072>] get_phy_device+0xd2/0x220
> [<ffffffff827e7844>] mdiobus_scan+0xa4/0x2e0
> [<ffffffff827e8be2>] __mdiobus_register+0x482/0x8b0
> [<ffffffffa01f5d24>] r6040_init_one+0x714/0xd2c [r6040]
> ...
>
> The problem occurs in probe process as follows:
> r6040_init_one:
> mdiobus_register
> mdiobus_scan <- alloc and register phy_device,
> the reference count of phy_device is 3
> r6040_mii_probe
> phy_connect <- connect to the first phy_device,
> so the reference count of the first
> phy_device is 4, others are 3
> register_netdev <- fault inject succeeded, goto error handling path
>
> // error handling path
> err_out_mdio_unregister:
> mdiobus_unregister(lp->mii_bus);
> err_out_mdio:
> mdiobus_free(lp->mii_bus); <- the reference count of the first
> phy_device is 1, it is not released
> and other phy_devices are released
> // similarly, the remove process also has the same problem
>
> The root cause is traced to the phy_device is not disconnected when
> removes one r6040 device in r6040_remove_one() or on error handling path
> after r6040_mii probed successfully. In r6040_mii_probe(), a net ethernet
> device is connected to the first PHY device of mii_bus, in order to
> notify the connected driver when the link status changes, which is the
> default behavior of the PHY infrastructure to handle everything.
> Therefore the phy_device should be disconnected when removes one r6040
> device or on error handling path.
>
> Fix it by adding phy_disconnect() when removes one r6040 device or on
> error handling path after r6040_mii probed successfully.
>
> Fixes: 3831861b4ad8 ("r6040: implement phylib")
> Signed-off-by: Li Zetao <[email protected]>
> ---
> v1 -> v2: change the subject prefix "PATCH" to "PATCH net" and change
> the goto label name "err_out_r6040_mii_remove" to "err_out_phy_disconnect"
>
> drivers/net/ethernet/rdc/r6040.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
Please don't send new patches as reply-to.
Thanks,
Reviewed-by: Leon Romanovsky <[email protected]>