From patchwork Wed Apr 14 08:57:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 421355 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=-15.8 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 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 6EA2EC433B4 for ; Wed, 14 Apr 2021 09:01:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51B88613D5 for ; Wed, 14 Apr 2021 09:01:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237964AbhDNJBS (ORCPT ); Wed, 14 Apr 2021 05:01:18 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:47098 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350331AbhDNJBB (ORCPT ); Wed, 14 Apr 2021 05:01:01 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 13E8tVXk072503; Wed, 14 Apr 2021 08:58:13 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 : in-reply-to; s=corp-2020-01-29; bh=En+uOg9GFocC1SYz6W2EUz02GPeroGC/7J/dzkiPHJg=; b=owc89vWCSuernGisM2V2yloJE7VDIss1WJJyjOeTQ46d8sX8Pk7tMEMQCvjyjr5V4IHP JqjDjbGaRr3/rN4iNfzXdnJOrsNk92esGei/xUS6we9Nwfa2XCfMdqfhUgw9af/jB9Fp m01jQOo3A2i52Ka9Tc8l48+/YRE0uc0Kk88+KyMArc2WUVpz+QXsl4HHKbR3R9hq+cCf oJspeofubzYYnUyBFo/XQbAuGCxgCU95dofRDCy9blFucxnGlL3v9GVp599RHkkyzPpL kZURL99EnS97KJuWOd57PcTuTztFdiYVq01EsCoC0HQ6xfailNMLgdAslHgz2wFHs8bt OQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2120.oracle.com with ESMTP id 37u4nnhnuc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 14 Apr 2021 08:58:13 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 13E8tj58096437; Wed, 14 Apr 2021 08:58:11 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3020.oracle.com with ESMTP id 37unx1131j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 14 Apr 2021 08:58:11 +0000 Received: from abhmp0007.oracle.com (abhmp0007.oracle.com [141.146.116.13]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 13E8w6SN023662; Wed, 14 Apr 2021 08:58:06 GMT Received: from mwanda (/10.175.166.128) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 14 Apr 2021 01:58:05 -0700 Date: Wed, 14 Apr 2021 11:57:59 +0300 From: Dan Carpenter To: Stefan Richter , Luo Likang Cc: security@kernel.org, linux-distros@vs.openwall.org, Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux1394-devel@lists.sourceforge.net Subject: [PATCH] media: firewire: firedtv-avc: fix a buffer overflow in avc_ca_pmt() Message-ID: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <000001d73031$d5304480$7f90cd80$@nsfocus.com> X-Mailer: git-send-email haha only kidding X-Proofpoint-IMR: 1 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9953 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 suspectscore=0 mlxscore=0 malwarescore=0 adultscore=0 bulkscore=0 spamscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104140063 X-Proofpoint-ORIG-GUID: _Albd3AHUy9Ljndxg5nYNJESfSKDAPd_ X-Proofpoint-GUID: _Albd3AHUy9Ljndxg5nYNJESfSKDAPd_ X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9953 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 phishscore=0 suspectscore=0 mlxlogscore=999 priorityscore=1501 clxscore=1011 lowpriorityscore=0 spamscore=0 impostorscore=0 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104140063 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The bounds checking in avc_ca_pmt() is not strict enough. It should be checking "read_pos + 4" because it's reading 5 bytes. If the "es_info_length" is non-zero then it reads a 6th byte so there needs to be an additional check for that. I also added checks for the "write_pos". I don't think these are required because "read_pos" and "write_pos" are tied together so checking one ought to be enough. But they make the code easier to understand for me. The other problem is that "length" can be invalid. It comes from "data_length" in fdtv_ca_pmt(). Cc: stable@vger.kernel.org Reported-by: Luo Likang Signed-off-by: Dan Carpenter --- This hardware isn't super common so there is no embargo. Resending through normal lists. Oh, another thing is the data_length calculation in fdtv_ca_pmt() seems very suspicous. Reading more than 4 bytes in the loop will lead to shift wrapping. drivers/media/firewire/firedtv-avc.c | 14 +++++++++++--- drivers/media/firewire/firedtv-ci.c | 2 ++ 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/media/firewire/firedtv-avc.c b/drivers/media/firewire/firedtv-avc.c index 2bf9467b917d..71991f8638e6 100644 --- a/drivers/media/firewire/firedtv-avc.c +++ b/drivers/media/firewire/firedtv-avc.c @@ -1165,7 +1165,11 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length) read_pos += program_info_length; write_pos += program_info_length; } - while (read_pos < length) { + while (read_pos + 4 < length) { + if (write_pos + 4 >= sizeof(c->operand) - 4) { + ret = -EINVAL; + goto out; + } c->operand[write_pos++] = msg[read_pos++]; c->operand[write_pos++] = msg[read_pos++]; c->operand[write_pos++] = msg[read_pos++]; @@ -1177,13 +1181,17 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length) c->operand[write_pos++] = es_info_length >> 8; c->operand[write_pos++] = es_info_length & 0xff; if (es_info_length > 0) { + if (read_pos >= length) { + ret = -EINVAL; + goto out; + } pmt_cmd_id = msg[read_pos++]; if (pmt_cmd_id != 1 && pmt_cmd_id != 4) dev_err(fdtv->device, "invalid pmt_cmd_id %d at stream level\n", pmt_cmd_id); - if (es_info_length > sizeof(c->operand) - 4 - - write_pos) { + if (es_info_length > sizeof(c->operand) - 4 - write_pos || + es_info_length > length - read_pos) { ret = -EINVAL; goto out; } diff --git a/drivers/media/firewire/firedtv-ci.c b/drivers/media/firewire/firedtv-ci.c index 9363d005e2b6..2d6992ac5dd6 100644 --- a/drivers/media/firewire/firedtv-ci.c +++ b/drivers/media/firewire/firedtv-ci.c @@ -134,6 +134,8 @@ static int fdtv_ca_pmt(struct firedtv *fdtv, void *arg) } else { data_length = msg->msg[3]; } + if (data_length > sizeof(msg->msg) - 4) + return -EINVAL; return avc_ca_pmt(fdtv, &msg->msg[data_pos], data_length); }