From patchwork Thu Jul 8 07:37:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yajun Deng X-Patchwork-Id: 471684 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 957B4C07E96 for ; Thu, 8 Jul 2021 07:38:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6ED4A61C59 for ; Thu, 8 Jul 2021 07:38:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230492AbhGHHlD (ORCPT ); Thu, 8 Jul 2021 03:41:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229838AbhGHHlC (ORCPT ); Thu, 8 Jul 2021 03:41:02 -0400 Received: from out2.migadu.com (out2.migadu.com [IPv6:2001:41d0:2:aacc::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26779C061574; Thu, 8 Jul 2021 00:38:21 -0700 (PDT) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1625729895; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=4zHBxaMAyTXtQ6h+HyhVoICHa4hb51TQtMkMoZjY9QQ=; b=ov8Z0rkyn7MGj7v9Z2mO2dCNaOvADpf/PHqvEaB1gEFBcNMOpGMzSZEa14blNHSrxsGGS+ zXJnAMr4YNq2WL9T4EwfPRYyNYKTJdVTi0vEci/vTiAecsMGKJ8wBQN9z4tzCi+KM0ejAK 6/Kzt/njNyT1bwzCTHv7D2egZbf8Vsk= From: Yajun Deng To: davem@davemloft.net, kuba@kernel.org, ryazanov.s.a@gmail.com, johannes.berg@intel.com, avagin@gmail.com, vladimir.oltean@nxp.com, cong.wang@bytedance.com, roopa@cumulusnetworks.com, yajun.deng@linux.dev, zhudi21@huawei.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] net: rtnetlink: Fix rtnl_dereference return value is NULL Date: Thu, 8 Jul 2021 15:37:45 +0800 Message-Id: <20210708073745.13797-1-yajun.deng@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: yajun.deng@linux.dev Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org rtnl_dereference() may be return NULL in rtnl_unregister(), so add this case handling. Signed-off-by: Yajun Deng --- net/core/rtnetlink.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index f6af3e74fc44..57ce22669b06 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -289,24 +289,27 @@ int rtnl_unregister(int protocol, int msgtype) struct rtnl_link __rcu **tab; struct rtnl_link *link; int msgindex; + int ret = -ENOENT; BUG_ON(protocol < 0 || protocol > RTNL_FAMILY_MAX); msgindex = rtm_msgindex(msgtype); rtnl_lock(); tab = rtnl_dereference(rtnl_msg_handlers[protocol]); - if (!tab) { - rtnl_unlock(); - return -ENOENT; - } + if (!tab) + goto unlock; link = rtnl_dereference(tab[msgindex]); - rcu_assign_pointer(tab[msgindex], NULL); - rtnl_unlock(); + if (!link) + goto unlock; + rcu_assign_pointer(tab[msgindex], NULL); kfree_rcu(link, rcu); + ret = 0; - return 0; +unlock: + rtnl_unlock(); + return ret; } EXPORT_SYMBOL_GPL(rtnl_unregister);