From patchwork Mon Aug 3 12:20:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 266856 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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 1A2DBC433DF for ; Mon, 3 Aug 2020 12:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE411204EC for ; Mon, 3 Aug 2020 12:38:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596458322; bh=tujbRiMNP8VhyjSC5XmQF9JXfrHEXn0HLrVaRZJ/q+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EE0ieJRLhTDtIym79qCbBacyDIK4LISS3V7ql2b9dSo+4c6anBzwt2CxkPq6D8+Qs j+I42P0JLAHtpFuSpOqhZd2UEDHi4AAXNUmwztu5e0902vXX4dJ4oteSGxOBOfcm3b n0iYv7SDg2TAAWeiqCjfg5lOgqzrr1fyKxuYYh84= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728846AbgHCMik (ORCPT ); Mon, 3 Aug 2020 08:38:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:34560 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729552AbgHCMeZ (ORCPT ); Mon, 3 Aug 2020 08:34:25 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0EABF204EC; Mon, 3 Aug 2020 12:34:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596458064; bh=tujbRiMNP8VhyjSC5XmQF9JXfrHEXn0HLrVaRZJ/q+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vOZCcuNU/oOmSwHgF8jzLLKWvXGXGHpYLJghhldao5eR9gGuBfL4stCe2pYzoH+Ug +D2bIQBM35tgyfxgpzxIINzuF2txCX28eGh8uaGQ8kPf4kk+guR89J1cu+q6nh3Kck EcSSvmGL7iV7dwFSQgz/NR7EvxuakdF5gSSP+2Pc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , "David S. Miller" Subject: [PATCH 4.14 26/51] net/x25: Fix x25_neigh refcnt leak when x25 disconnect Date: Mon, 3 Aug 2020 14:20:11 +0200 Message-Id: <20200803121850.800444828@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200803121849.488233135@linuxfoundation.org> References: <20200803121849.488233135@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiyu Yang commit 4becb7ee5b3d2829ed7b9261a245a77d5b7de902 upstream. x25_connect() invokes x25_get_neigh(), which returns a reference of the specified x25_neigh object to "x25->neighbour" with increased refcnt. When x25 connect success and returns, the reference still be hold by "x25->neighbour", so the refcount should be decreased in x25_disconnect() to keep refcount balanced. The reference counting issue happens in x25_disconnect(), which forgets to decrease the refcnt increased by x25_get_neigh() in x25_connect(), causing a refcnt leak. Fix this issue by calling x25_neigh_put() before x25_disconnect() returns. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/x25/x25_subr.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/x25/x25_subr.c +++ b/net/x25/x25_subr.c @@ -363,6 +363,10 @@ void x25_disconnect(struct sock *sk, int sk->sk_state_change(sk); sock_set_flag(sk, SOCK_DEAD); } + read_lock_bh(&x25_list_lock); + x25_neigh_put(x25->neighbour); + x25->neighbour = NULL; + read_unlock_bh(&x25_list_lock); } /*