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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 2D3F6C352BE for ; Sat, 18 Apr 2020 20:26:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0204321D93 for ; Sat, 18 Apr 2020 20:26:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728206AbgDRU0R (ORCPT ); Sat, 18 Apr 2020 16:26:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726014AbgDRU0Q (ORCPT ); Sat, 18 Apr 2020 16:26:16 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DC30C061A0C; Sat, 18 Apr 2020 13:26:16 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 5574912753E8B; Sat, 18 Apr 2020 13:26:15 -0700 (PDT) Date: Sat, 18 Apr 2020 13:26:14 -0700 (PDT) Message-Id: <20200418.132614.92642620154751485.davem@davemloft.net> To: xiyuyang19@fudan.edu.cn Cc: jmaloy@redhat.com, ying.xue@windriver.com, kuba@kernel.org, netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org, yuanxzhang@fudan.edu.cn, kjlu@umn.edu, tanxin.ctf@gmail.com Subject: Re: [PATCH] tipc: Fix potential tipc_node refcnt leak in tipc_rcv From: David Miller In-Reply-To: <1586940029-69994-1-git-send-email-xiyuyang19@fudan.edu.cn> References: <1586940029-69994-1-git-send-email-xiyuyang19@fudan.edu.cn> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Sat, 18 Apr 2020 13:26:15 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiyu Yang Date: Wed, 15 Apr 2020 16:40:28 +0800 > tipc_rcv() invokes tipc_node_find() twice, which returns a reference of > the specified tipc_node object to "n" with increased refcnt. > > When tipc_rcv() returns or a new object is assigned to "n", the original > local reference of "n" becomes invalid, so the refcount should be > decreased to keep refcount balanced. > > The issue happens in some paths of tipc_rcv(), which forget to decrease > the refcnt increased by tipc_node_find() and will cause a refcnt leak. > > Fix this issue by calling tipc_node_put() before the original object > pointed by "n" becomes invalid. > > Signed-off-by: Xiyu Yang > Signed-off-by: Xin Tan Applied and queued up for -stable.