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=-19.4 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 13230C433ED for ; Wed, 12 May 2021 14:55:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D67A561425 for ; Wed, 12 May 2021 14:55:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232348AbhELO4v (ORCPT ); Wed, 12 May 2021 10:56:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:46142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232167AbhELOzb (ORCPT ); Wed, 12 May 2021 10:55:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BB2B161413; Wed, 12 May 2021 14:54:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620831263; bh=XOWtBRHSuOX4EissREp2XcPj4qBiqUOKAOx7vuhzsuc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VLPzf9uC74TaiLlJbXNn+hHiFkTDyKWq05HbZ0xd820cVCIm3gOiuGy0FRoTeEpuh MVl0dqAaEt+b+ToF5qSLwOkube3AdxVvj46BqAB4LAT1+8L/4h6L1U6QPMBa8yM9c0 r0ZZaUOiWLV44PrpsMnWceMrFxUIhz7BFk4chqes= 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 5.4 004/244] net/nfc: fix use-after-free llcp_sock_bind/connect Date: Wed, 12 May 2021 16:46:15 +0200 Message-Id: <20210512144743.183367973@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144743.039977287@linuxfoundation.org> References: <20210512144743.039977287@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 @@ -109,12 +109,14 @@ 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; @@ -709,6 +711,7 @@ 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; } @@ -756,6 +759,7 @@ sock_unlink: sock_llcp_release: nfc_llcp_put_ssap(local, llcp_sock->ssap); nfc_llcp_local_put(llcp_sock->local); + llcp_sock->local = NULL; put_dev: nfc_put_device(dev);