From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F64EC04FDE for ; Tue, 13 Dec 2022 09:29:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234844AbiLMJ3J (ORCPT ); Tue, 13 Dec 2022 04:29:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234816AbiLMJ3F (ORCPT ); Tue, 13 Dec 2022 04:29:05 -0500 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA00E627C; Tue, 13 Dec 2022 01:29:03 -0800 (PST) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4NWY7k2zvHzRpt4; Tue, 13 Dec 2022 17:28:02 +0800 (CST) Received: from [10.174.178.165] (10.174.178.165) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Tue, 13 Dec 2022 17:29:01 +0800 Message-ID: <7f35ca55-cbed-98ac-4988-1b783db21dc5@huawei.com> Date: Tue, 13 Dec 2022 17:29:00 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.5.1 Subject: Re: [PATCH] r6040: Fix kmemleak in probe and remove To: Li Zetao , "f.fainelli@gmail.com" , "davem@davemloft.net" , "edumazet@google.com" , "kuba@kernel.org" , "pabeni@redhat.com" CC: "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20221213101723.348289-1-lizetao1@huawei.com> From: Wei Yongjun In-Reply-To: <20221213101723.348289-1-lizetao1@huawei.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.178.165] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2022/12/13 18:17, 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: > [] kmalloc_trace+0x22/0x60 > [] phy_device_create+0x4e/0x90 > [] get_phy_device+0xd2/0x220 > [] mdiobus_scan+0xa4/0x2e0 > [] __mdiobus_register+0x482/0x8b0 > [] 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 > --- > drivers/net/ethernet/rdc/r6040.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Please use [PATCH net] ... format in title. > > diff --git a/drivers/net/ethernet/rdc/r6040.c b/drivers/net/ethernet/rdc/r6040.c > index eecd52ed1ed2..95b682597da1 100644 > --- a/drivers/net/ethernet/rdc/r6040.c > +++ b/drivers/net/ethernet/rdc/r6040.c > @@ -1159,10 +1159,12 @@ static int r6040_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) > err = register_netdev(dev); > if (err) { > dev_err(&pdev->dev, "Failed to register net device\n"); > - goto err_out_mdio_unregister; > + goto err_out_r6040_mii_remove; better to use something like 'err_out_phy_disconnect' > } > return 0; > > +err_out_r6040_mii_remove: > + phy_disconnect(dev->phydev); > err_out_mdio_unregister: > mdiobus_unregister(lp->mii_bus); > err_out_mdio: > @@ -1186,6 +1188,7 @@ static void r6040_remove_one(struct pci_dev *pdev) > struct r6040_private *lp = netdev_priv(dev); > > unregister_netdev(dev); > + phy_disconnect(dev->phydev); > mdiobus_unregister(lp->mii_bus); > mdiobus_free(lp->mii_bus); > netif_napi_del(&lp->napi);