From patchwork Wed Mar 3 06:16:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Xiaoming Ni X-Patchwork-Id: 393439 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 5293EC433E0 for ; Wed, 3 Mar 2021 13:42:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F02B664E74 for ; Wed, 3 Mar 2021 13:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383095AbhCCNkt (ORCPT ); Wed, 3 Mar 2021 08:40:49 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:12677 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355018AbhCCGRy (ORCPT ); Wed, 3 Mar 2021 01:17:54 -0500 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Dr3cx6l7dzlRhs; Wed, 3 Mar 2021 14:14:57 +0800 (CST) Received: from use12-sp2.huawei.com (10.67.189.174) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.498.0; Wed, 3 Mar 2021 14:16:59 +0800 From: Xiaoming Ni To: , , , , , , , , , , , CC: , , Subject: [PATCH 4/4] nfc: Avoid endless loops caused by repeated llcp_sock_connect() Date: Wed, 3 Mar 2021 14:16:54 +0800 Message-ID: <20210303061654.127666-5-nixiaoming@huawei.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210303061654.127666-1-nixiaoming@huawei.com> References: <20210303061654.127666-1-nixiaoming@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.189.174] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org When sock_wait_state() returns -EINPROGRESS, "sk->sk_state" is LLCP_CONNECTING. In this case, llcp_sock_connect() is repeatedly invoked, nfc_llcp_sock_link() will add sk to local->connecting_sockets twice. sk->sk_node->next will point to itself, that will make an endless loop and hang-up the system. To fix it, check whether sk->sk_state is LLCP_CONNECTING in llcp_sock_connect() to avoid repeated invoking. fix CVE-2020-25673 Fixes: b4011239a08e ("NFC: llcp: Fix non blocking sockets connections") Reported-by: "kiyin(尹亮)" Link: https://www.openwall.com/lists/oss-security/2020/11/01/1 Cc: #v3.11 Signed-off-by: Xiaoming Ni --- net/nfc/llcp_sock.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 59172614b249..a3b46f888803 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -673,6 +673,10 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, ret = -EISCONN; goto error; } + if (sk->sk_state == LLCP_CONNECTING) { + ret = -EINPROGRESS; + goto error; + } dev = nfc_get_device(addr->dev_idx); if (dev == NULL) {