From patchwork Thu Nov 26 13:23:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yingliang X-Patchwork-Id: 1406651 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=huawei.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Chdmp3l1Pz9sVh for ; Fri, 27 Nov 2020 00:25:46 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389956AbgKZNZd (ORCPT ); Thu, 26 Nov 2020 08:25:33 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:7739 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389760AbgKZNZc (ORCPT ); Thu, 26 Nov 2020 08:25:32 -0500 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4ChdlY68ChzkftB; Thu, 26 Nov 2020 21:24:41 +0800 (CST) Received: from huawei.com (10.175.103.91) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.487.0; Thu, 26 Nov 2020 21:25:02 +0800 From: Yang Yingliang To: CC: , , , , Subject: [PATCH net] net: fix memory leak in register_netdevice() on error path Date: Thu, 26 Nov 2020 21:23:12 +0800 Message-ID: <20201126132312.3593725-1-yangyingliang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.103.91] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org I got a memleak report when doing fault-inject test: unreferenced object 0xffff88810ace9000 (size 1024): comm "ip", pid 4622, jiffies 4295457037 (age 43.378s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000008abe41>] __kmalloc+0x10f/0x210 [<000000005d3533a6>] veth_dev_init+0x140/0x310 [<0000000088353c64>] register_netdevice+0x496/0x7a0 [<000000001324d322>] veth_newlink+0x40b/0x960 [<00000000d0799866>] __rtnl_newlink+0xd8c/0x1360 [<00000000d616040a>] rtnl_newlink+0x6b/0xa0 [<00000000e0a1600d>] rtnetlink_rcv_msg+0x3cc/0x9e0 [<000000009eeff98b>] netlink_rcv_skb+0x130/0x3a0 [<00000000500f8be1>] netlink_unicast+0x4da/0x700 [<00000000666c03b3>] netlink_sendmsg+0x7fe/0xcb0 [<0000000073b28103>] sock_sendmsg+0x143/0x180 [<00000000ad746a30>] ____sys_sendmsg+0x677/0x810 [<0000000087dd98e5>] ___sys_sendmsg+0x105/0x180 [<00000000028dd365>] __sys_sendmsg+0xf0/0x1c0 [<00000000a6bfbae6>] do_syscall_64+0x33/0x40 [<00000000e00521b4>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 It seems ifb and loopback may also hit the leak, so I try to fix this in register_netdevice(). In common case, priv_destructor() will be called in netdev_run_todo() after calling ndo_uninit() in rollback_registered(), on other error path in register_netdevice(), ndo_uninit() and priv_destructor() are called before register_netdevice() return, but in this case, priv_destructor() will never be called, then it causes memory leak, so we should call priv_destructor() here. Reported-by: Hulk Robot Signed-off-by: Yang Yingliang --- net/core/dev.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index 82dc6b48e45f..907204395b64 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -10000,6 +10000,17 @@ int register_netdevice(struct net_device *dev) ret = notifier_to_errno(ret); if (ret) { rollback_registered(dev); + /* + * In common case, priv_destructor() will be + * called in netdev_run_todo() after calling + * ndo_uninit() in rollback_registered(). + * But in this case, priv_destructor() will + * never be called, then it causes memory + * leak, so we should call priv_destructor() + * here. + */ + if (dev->priv_destructor) + dev->priv_destructor(dev); rcu_barrier(); dev->reg_state = NETREG_UNREGISTERED;