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=unavailable 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 A9C73C56202 for ; Tue, 17 Nov 2020 13:12:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 420F3241A5 for ; Tue, 17 Nov 2020 13:12:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZSBRLoUr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729743AbgKQNLu (ORCPT ); Tue, 17 Nov 2020 08:11:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:41288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729647AbgKQNLh (ORCPT ); Tue, 17 Nov 2020 08:11:37 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 53C1A246BE; Tue, 17 Nov 2020 13:11:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605618697; bh=KIjxkzgdOwMJoSiRdDNpZiJS6sgnIB69WrDcBfVwplk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZSBRLoUrpd+th3JeuErdtw1eAxPF1Ys7RtaGcWlLYMxEcsHc9clKZOWrtGBitwM9c QLBajTXwtFZ+txg+XdiGDtxhCA9Sa7ZSWZk7lCAKR7Cg8AmlR3/rUdGPZXaVbbuejD xozm3SVQLPl5KOfC3cHKKAzlFVupXmAwRwCipzug= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Schiller , Xie He , Jakub Kicinski Subject: [PATCH 4.9 55/78] net/x25: Fix null-ptr-deref in x25_connect Date: Tue, 17 Nov 2020 14:05:21 +0100 Message-Id: <20201117122111.815695041@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122109.116890262@linuxfoundation.org> References: <20201117122109.116890262@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Martin Schiller [ Upstream commit 361182308766a265b6c521879b34302617a8c209 ] This fixes a regression for blocking connects introduced by commit 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect"). The x25->neighbour is already set to "NULL" by x25_disconnect() now, while a blocking connect is waiting in x25_wait_for_connection_establishment(). Therefore x25->neighbour must not be accessed here again and x25->state is also already set to X25_STATE_0 by x25_disconnect(). Fixes: 4becb7ee5b3d ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect") Signed-off-by: Martin Schiller Reviewed-by: Xie He Link: https://lore.kernel.org/r/20201109065449.9014-1-ms@dev.tdt.de Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/x25/af_x25.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -823,7 +823,7 @@ static int x25_connect(struct socket *so sock->state = SS_CONNECTED; rc = 0; out_put_neigh: - if (rc) { + if (rc && x25->neighbour) { read_lock_bh(&x25_list_lock); x25_neigh_put(x25->neighbour); x25->neighbour = NULL;