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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 E2E1DC10F12 for ; Mon, 15 Apr 2019 19:05:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADC2B218A1 for ; Mon, 15 Apr 2019 19:05:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355128; bh=gmku6RqsM67ebLOu6DxW0dwT4QGytn6flDHxHcH6T2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1dBsk8tqS7RCIpwWWQpS5ouQ3iF2uGISTe/8FPvvcO3T1dBmarhSTkedpcEJYREPW +qJo5BaBxYQULfULAF4/MSbW5DA5aci2D6e7SlrvKlJ7Gg/JuQ2kMlEssEblFz6py0 mBkvZtNm/Jdsv25ot9beZIvfxlZDHHpUweZnampM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729158AbfDOTFZ (ORCPT ); Mon, 15 Apr 2019 15:05:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:39100 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729716AbfDOTFZ (ORCPT ); Mon, 15 Apr 2019 15:05:25 -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 44937218A1; Mon, 15 Apr 2019 19:05:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355124; bh=gmku6RqsM67ebLOu6DxW0dwT4QGytn6flDHxHcH6T2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z+oYnQfSNpd8EZqi88PLXVhwQtuynHNp+uDm3HRlpB1AZp5REtdzc/SZ+5qwoyPeb to9H4Lze4G9TpNUB9bdGkXAK/e+x5SSoyYFC1GlFEvCV5GzoZWUrvYEDBExMe9oYDy N5X6Dk03eJywG8Kg4PMCwgok7POsXNrjwx3VUWec= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dust Li , Eric Dumazet , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 022/101] tcp: fix a potential NULL pointer dereference in tcp_sk_exit Date: Mon, 15 Apr 2019 20:58:20 +0200 Message-Id: <20190415183741.556302042@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415183740.341577907@linuxfoundation.org> References: <20190415183740.341577907@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit b506bc975f60f06e13e74adb35e708a23dc4e87c ] When tcp_sk_init() failed in inet_ctl_sock_create(), 'net->ipv4.tcp_congestion_control' will be left uninitialized, but tcp_sk_exit() hasn't check for that. This patch add checking on 'net->ipv4.tcp_congestion_control' in tcp_sk_exit() to prevent NULL-ptr dereference. Fixes: 6670e1524477 ("tcp: Namespace-ify sysctl_tcp_default_congestion_control") Signed-off-by: Dust Li Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_ipv4.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 30fdf891940b..11101cf8693b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2490,7 +2490,8 @@ static void __net_exit tcp_sk_exit(struct net *net) { int cpu; - module_put(net->ipv4.tcp_congestion_control->owner); + if (net->ipv4.tcp_congestion_control) + module_put(net->ipv4.tcp_congestion_control->owner); for_each_possible_cpu(cpu) inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.tcp_sk, cpu)); -- 2.19.1