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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 B4DFDC433ED for ; Thu, 20 May 2021 11:10:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 950EC60200 for ; Thu, 20 May 2021 11:10:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239344AbhETLLd (ORCPT ); Thu, 20 May 2021 07:11:33 -0400 Received: from mail.kernel.org ([198.145.29.99]:52068 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239110AbhETKvs (ORCPT ); Thu, 20 May 2021 06:51:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 52EAE617C9; Thu, 20 May 2021 10:00:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621504804; bh=UX0XKPTdDTy/mbmYjVl+qgSNN60V0sjiGcON+9tifMY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JNQ//R2zRnH7MDJ0c/XW+3BjIYKMtlQEupPE+NAFPC0c1uqla7Irtrfe0eWscPO6J H3Xi7DyMKbmPXEeljGFrhXCv55F2UCsnGnAo+hvDoG5IxqcOrOqpig9mkMUzPS+UIb nqHG18ZwAjIwCNfmhTtB9w5a1BuY/p4/aEe8TYUo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Or Cohen , Nadav Markus , "David S. Miller" Subject: [PATCH 4.9 071/240] net/nfc: fix use-after-free llcp_sock_bind/connect Date: Thu, 20 May 2021 11:21:03 +0200 Message-Id: <20210520092111.063684823@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092108.587553970@linuxfoundation.org> References: <20210520092108.587553970@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: Or Cohen commit c61760e6940dd4039a7f5e84a6afc9cdbf4d82b6 upstream. Commits 8a4cd82d ("nfc: fix refcount leak in llcp_sock_connect()") and c33b1cc62 ("nfc: fix refcount leak in llcp_sock_bind()") fixed a refcount leak bug in bind/connect but introduced a use-after-free if the same local is assigned to 2 different sockets. This can be triggered by the following simple program: int sock1 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP ); int sock2 = socket( AF_NFC, SOCK_STREAM, NFC_SOCKPROTO_LLCP ); memset( &addr, 0, sizeof(struct sockaddr_nfc_llcp) ); addr.sa_family = AF_NFC; addr.nfc_protocol = NFC_PROTO_NFC_DEP; bind( sock1, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) ) bind( sock2, (struct sockaddr*) &addr, sizeof(struct sockaddr_nfc_llcp) ) close(sock1); close(sock2); Fix this by assigning NULL to llcp_sock->local after calling nfc_llcp_local_put. This addresses CVE-2021-23134. Reported-by: Or Cohen Reported-by: Nadav Markus Fixes: c33b1cc62 ("nfc: fix refcount leak in llcp_sock_bind()") Signed-off-by: Or Cohen Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/nfc/llcp_sock.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -120,12 +120,14 @@ static int llcp_sock_bind(struct socket GFP_KERNEL); if (!llcp_sock->service_name) { nfc_llcp_local_put(llcp_sock->local); + llcp_sock->local = NULL; ret = -ENOMEM; goto put_dev; } llcp_sock->ssap = nfc_llcp_get_sdp_ssap(local, llcp_sock); if (llcp_sock->ssap == LLCP_SAP_MAX) { nfc_llcp_local_put(llcp_sock->local); + llcp_sock->local = NULL; kfree(llcp_sock->service_name); llcp_sock->service_name = NULL; ret = -EADDRINUSE; @@ -721,6 +723,7 @@ static int llcp_sock_connect(struct sock llcp_sock->ssap = nfc_llcp_get_local_ssap(local); if (llcp_sock->ssap == LLCP_SAP_MAX) { nfc_llcp_local_put(llcp_sock->local); + llcp_sock->local = NULL; ret = -ENOMEM; goto put_dev; } @@ -759,6 +762,7 @@ static int llcp_sock_connect(struct sock sock_unlink: nfc_llcp_put_ssap(local, llcp_sock->ssap); nfc_llcp_local_put(llcp_sock->local); + llcp_sock->local = NULL; nfc_llcp_sock_unlink(&local->connecting_sockets, sk); kfree(llcp_sock->service_name);