From patchwork Tue May 5 08:25:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Carpenter X-Patchwork-Id: 11528411 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 55D7C1392 for ; Tue, 5 May 2020 08:26:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E5F72075E for ; Tue, 5 May 2020 08:26:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="zAucqM8Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728114AbgEEI0L (ORCPT ); Tue, 5 May 2020 04:26:11 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:35792 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725320AbgEEI0L (ORCPT ); Tue, 5 May 2020 04:26:11 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0458N6ZD135107; Tue, 5 May 2020 08:26:06 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; s=corp-2020-01-29; bh=vfafqK+gClVsvD0wGa8+iFWiZuHNuS1IxnHzPnTCGTA=; b=zAucqM8ZjJy1x3vZA+k83i6bRxzTkfEJ19ggLKPhVgYhmAoEk4YqtZFWfcAnajXXiRtp RPD0TnvXpy0Ym9pMxZR6LYU58GNzfSW1JyzDW70j9xG3PuhZUlYbVbsueqeQACfgu/fd TuuUG0v1awhPeVaIoRD6Do313dW7ymFy1CHpVJ1YgEltf5BDuMvkuuO1DCNhJZISvFUZ ik+P6S49SoyYsZkPZUq7jIi8XNX4evtBM6jKtBMLQukYTzBvxlehii4twyvxah7qV/fe GovyL9959VQ/Bht9G+fzVSPAiA7xR2b1RvIpwgrxNSV7DBKvvOTH2VNKA4D+cE+ch2+u iQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 30s0tmb86p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 05 May 2020 08:26:06 +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 0458NNYO132559; Tue, 5 May 2020 08:26:05 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3020.oracle.com with ESMTP id 30sjndqsdk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 05 May 2020 08:26:05 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0458Q3SN014522; Tue, 5 May 2020 08:26:03 GMT Received: from mwanda (/41.57.98.10) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 05 May 2020 01:26:03 -0700 Date: Tue, 5 May 2020 11:25:56 +0300 From: Dan Carpenter To: Hans Verkuil Cc: Mauro Carvalho Chehab , Dariusz Marcinkiewicz , Kamil Debski , linux-media@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] media: cec: silence shift wrapping warning in __cec_s_log_addrs() Message-ID: <20200505082556.GA113134@mwanda> MIME-Version: 1.0 Content-Disposition: inline X-Mailer: git-send-email haha only kidding X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9611 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 adultscore=0 phishscore=0 mlxlogscore=999 bulkscore=0 malwarescore=0 spamscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005050067 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9611 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxscore=0 priorityscore=1501 lowpriorityscore=0 spamscore=0 suspectscore=0 phishscore=0 clxscore=1011 bulkscore=0 mlxlogscore=999 adultscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2005050067 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The log_addrs->log_addr_type[i] value is a u8 which is controlled by the user and comes from the ioctl. If it's over 31 then that results in undefined behavior (shift wrapping) and that leads to a Smatch static checker warning. We already cap the value later so we can silence the warning just by re-ordering the existing checks. I think the UBSan checker will also catch this bug at runtime and generate a warning. But otherwise the bug is harmless. Fixes: 9881fe0ca187 ("[media] cec: add HDMI CEC framework (adapter)") Signed-off-by: Dan Carpenter --- I haven't pushed the Smatch check for this but I've been re-working how user data is tracked and hopefully it should reach acceptable false positive ratio soon so I can do that. drivers/media/cec/core/cec-adap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/media/cec/core/cec-adap.c b/drivers/media/cec/core/cec-adap.c index 6c95dc471d4c6..6a04d19a96b2e 100644 --- a/drivers/media/cec/core/cec-adap.c +++ b/drivers/media/cec/core/cec-adap.c @@ -1734,6 +1734,10 @@ int __cec_s_log_addrs(struct cec_adapter *adap, unsigned j; log_addrs->log_addr[i] = CEC_LOG_ADDR_INVALID; + if (log_addrs->log_addr_type[i] > CEC_LOG_ADDR_TYPE_UNREGISTERED) { + dprintk(1, "unknown logical address type\n"); + return -EINVAL; + } if (type_mask & (1 << log_addrs->log_addr_type[i])) { dprintk(1, "duplicate logical address type\n"); return -EINVAL; @@ -1754,10 +1758,6 @@ int __cec_s_log_addrs(struct cec_adapter *adap, dprintk(1, "invalid primary device type\n"); return -EINVAL; } - if (log_addrs->log_addr_type[i] > CEC_LOG_ADDR_TYPE_UNREGISTERED) { - dprintk(1, "unknown logical address type\n"); - return -EINVAL; - } for (j = 0; j < feature_sz; j++) { if ((features[j] & 0x80) == 0) { if (op_is_dev_features)