From patchwork Tue Dec 1 15:15:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 11943145 X-Patchwork-Delegate: kuba@kernel.org 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=-17.2 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, UNPARSEABLE_RELAY,URIBL_BLOCKED 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 21C14C64E90 for ; Tue, 1 Dec 2020 15:22:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEE8422244 for ; Tue, 1 Dec 2020 15:22:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="RV4iVKxi" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391584AbgLAPWe (ORCPT ); Tue, 1 Dec 2020 10:22:34 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:36076 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390132AbgLAPWd (ORCPT ); Tue, 1 Dec 2020 10:22:33 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B1FBOo0165710; Tue, 1 Dec 2020 15:15:26 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type : content-transfer-encoding : in-reply-to; s=corp-2020-01-29; bh=FrOA1XUFmPKn8mKk+UnDtvZGiAQ6NVgplGG9s+uq6wU=; b=RV4iVKxim1xX5+cg5G9TC04TjU2egA+AW/3svD3xDSakxXrHwW9NWePfJjou7ivxwMZQ zC2A7FdPXWe5gKWkL8llp0LukPL3tEyAadOcJG/nDdnZxt6FWvZ8LbHOuYMa0ehQBEb9 iD5cBqfDKVP0wGCVQU41n+YlaJCNy0VtAn5FbnLOMXKrKZ88VosqRPbB03k8UhM3Cs2R DfWjs54RatvoeAaQEvbxKcNZEiCPsauPNHRhCO6cPdr7WFv9v3s7b9jVSIT2uhT+rfOi kdvT6vgOtVW7z3AoQftch5HBDrGRvbhxqW6n9iaxfflcTmR2VG8J06iTgUDZqv3S/6mm jg== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 353dyqk2aq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 01 Dec 2020 15:15:25 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B1FAP3v066373; Tue, 1 Dec 2020 15:15:25 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 35404n0anr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Dec 2020 15:15:25 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0B1FFKqd023845; Tue, 1 Dec 2020 15:15:20 GMT Received: from mwanda (/102.36.221.92) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 01 Dec 2020 07:15:19 -0800 Date: Tue, 1 Dec 2020 18:15:12 +0300 From: Dan Carpenter To: Martin Schiller Cc: "David S. Miller" , Jakub Kicinski , linux-x25@vger.kernel.org, netdev@vger.kernel.org, Andrew Hendry , =?utf-8?b?a2l5aW4o5bC55LquKQ==?= , security@kernel.org, linux-distros@vs.openwall.org, =?utf-8?b?aHVudGNoZW4o6ZmI6ZizKQ==?= , =?utf-8?b?ZGFu?= =?utf-8?b?bnl3YW5nKOeOi+Wuhyk=?= , kernel-janitors@vger.kernel.org Subject: [PATCH net v2] net/x25: prevent a couple of overflows Message-ID: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Mailer: git-send-email haha only kidding X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9822 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 bulkscore=0 malwarescore=0 mlxscore=0 mlxlogscore=999 phishscore=0 spamscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012010097 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9822 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 bulkscore=0 clxscore=1015 mlxscore=0 spamscore=0 priorityscore=1501 mlxlogscore=999 suspectscore=0 lowpriorityscore=0 phishscore=0 adultscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012010097 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org The .x25_addr[] address comes from the user and is not necessarily NUL terminated. This leads to a couple problems. The first problem is that the strlen() in x25_bind() can read beyond the end of the buffer. The second problem is more subtle and could result in memory corruption. The call tree is: x25_connect() --> x25_write_internal() --> x25_addr_aton() The .x25_addr[] buffers are copied to the "addresses" buffer from x25_write_internal() so it will lead to stack corruption. Verify that the strings are NUL terminated and return -EINVAL if they are not. Reported-by: "kiyin(尹亮)" Signed-off-by: Dan Carpenter Acked-by: Martin Schiller --- The first patch put a NUL terminator on the end of the string and this patch returns an error instead. I don't have a strong preference, which patch to go with. net/x25/af_x25.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 9232cdb42ad9..d41fffb2507b 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -675,7 +675,8 @@ static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) int len, i, rc = 0; if (addr_len != sizeof(struct sockaddr_x25) || - addr->sx25_family != AF_X25) { + addr->sx25_family != AF_X25 || + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) { rc = -EINVAL; goto out; } @@ -769,7 +770,8 @@ static int x25_connect(struct socket *sock, struct sockaddr *uaddr, rc = -EINVAL; if (addr_len != sizeof(struct sockaddr_x25) || - addr->sx25_family != AF_X25) + addr->sx25_family != AF_X25 || + strnlen(addr->sx25_addr.x25_addr, X25_ADDR_LEN) == X25_ADDR_LEN) goto out; rc = -ENETUNREACH;