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=-9.8 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 46BFBC433E1 for ; Thu, 20 Aug 2020 10:19:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1806E22B40 for ; Thu, 20 Aug 2020 10:19:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597918740; bh=pZOtxjNjinvQ+Xpqra3fbMQc09FWVo9+DFkPcY/6nzw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eem3llqU80Bw4ZoCzT0I4w9UYs4dycSDFmCZ4FNRoj/tSchrLe/zkemx3ninTmzTb oH40WhTji0XyvXwpEf6xjIDumJtF4L/dkTnj1iVQxneAcAKHeOm8qhEFt/nupvKzFU tzW+oR1M3FI7pT8nfuT0rWdzJ8lmu85aNMVFSwhs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731425AbgHTKS7 (ORCPT ); Thu, 20 Aug 2020 06:18:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:38576 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729583AbgHTKRX (ORCPT ); Thu, 20 Aug 2020 06:17:23 -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 3A3B72067C; Thu, 20 Aug 2020 10:17:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597918642; bh=pZOtxjNjinvQ+Xpqra3fbMQc09FWVo9+DFkPcY/6nzw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X2/znE5iUEKpzPcLvd7IcGtFFodjEadriWWInYwfuXyILV/SRUrbaF4UAwnBnAppx Lwby98lFbNCfCbIMm01sa2+Nqx+pTMqN+eaFUhIeo66ZuV9q2PO8WVYRg1UfB4VVmd GWCQ+lh9siMehMiKBD4d6VaYcy6kxhC0F+PeTDxk= 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 4.4 015/149] net/x25: Fix x25_neigh refcnt leak when x25 disconnect Date: Thu, 20 Aug 2020 11:21:32 +0200 Message-Id: <20200820092126.434763188@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820092125.688850368@linuxfoundation.org> References: <20200820092125.688850368@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -368,6 +368,10 @@ 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); } /*