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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 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 C8C95C33CA8 for ; Mon, 13 Jan 2020 08:49:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9CF4D207FF for ; Mon, 13 Jan 2020 08:49:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="QAtIetbI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728895AbgAMItS (ORCPT ); Mon, 13 Jan 2020 03:49:18 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:49288 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728783AbgAMItR (ORCPT ); Mon, 13 Jan 2020 03:49:17 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00D8mev4053829; Mon, 13 Jan 2020 08:49:08 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : content-transfer-encoding : in-reply-to; s=corp-2019-08-05; bh=lMx21tGcjb+jsEbRtABZz15Zz4x8qwLIqH7vx+tLHy0=; b=QAtIetbIzElkUUiTe/pxyaKmXwng6vbZ1v5NDNRT6l/qp1JS3dBkZkyiM/1dtc1qwIwu E0a6NJRrmGjM8dcXr8cuk449QA3F4Xj0ibSDrO/mtExqscsX5n9seKFhYEFRsx+GB7C0 AIrxB2FjJM7mW6+0ihQhgU61iuQaQM+DoQISkaGyM5+8x2wAaChEZ7dnsu2VOVKxvIjM 0yrNFv2/J/JzI6WzXtoRMzV1XPZjwKha7z7xssCN/3YOMkyHkA16kWehp54NBajgsBYl MoglJSF6brE6dEgxZZ8pXGfaaWpsEKuKBELD+XanouscNtmkghxuuMnxTdX109e6OsKt 4w== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 2xf73tdgdy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 Jan 2020 08:49:08 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 00D8n4gM117794; Mon, 13 Jan 2020 08:49:08 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 2xfqvpxaen-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 Jan 2020 08:49:07 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 00D8m2Ue014690; Mon, 13 Jan 2020 08:48:02 GMT Received: from kadam (/129.205.23.165) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 13 Jan 2020 00:48:01 -0800 Date: Mon, 13 Jan 2020 11:47:53 +0300 From: Dan Carpenter To: Marion & Christophe JAILLET Cc: Colin King , David Miller , linux-wireless@vger.kernel.org, "netdev@vger.kernel.org" , Kernel Janitors , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH][next] ath11k: avoid null pointer dereference when pointer band is null Message-ID: <20200113084753.GA9510@kadam> References: <05d5d54e035e4d69ad4ffb4a835a495a@huawei.com> <64797126-0c77-4c2c-ad2b-29d7af452c13@wanadoo.fr> <17571eee-9d72-98cb-00f5-d714a28b853b@wanadoo.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <17571eee-9d72-98cb-00f5-d714a28b853b@wanadoo.fr> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9498 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001130074 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9498 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2001130074 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sat, Jan 11, 2020 at 12:57:11PM +0100, Marion & Christophe JAILLET wrote: > Le 11/01/2020 à 10:50, linmiaohe a écrit : > > Colin Ian King wrote： > > > From: Colin Ian King > > > > > > In the unlikely event that cap->supported_bands has neither WMI_HOST_WLAN_2G_CAP set or WMI_HOST_WLAN_5G_CAP set then pointer band is null and a null dereference occurs when assigning > > > band->n_iftype_data. Move the assignment to the if blocks to > > > avoid this. Cleans up static analysis warnings. > > > > > > Addresses-Coverity: ("Explicit null dereference") > > > Fixes: 9f056ed8ee01 ("ath11k: add HE support") > > > Signed-off-by: Colin Ian King > > > --- > > > drivers/net/wireless/ath/ath11k/mac.c | 8 ++++---- > > > 1 file changed, 4 insertions(+), 4 deletions(-) > > It looks fine for me. Thanks. > > Reviewed-by: Miaohe Lin > (sorry for incomplete mail and mailing list addresses, my newsreader ate > them, and I cannot get the list from get_maintainer.pl because my (outdated) > tree does not have ath11k/... > I've only including the ones in memory of my mail writer. > > Please forward if needed) > > > Hi > > Shouldn't there be a > > | > > - band->n_iftype_data = count; at the end of the patch if the assignment > is *moved*? Without it, 'band' (as well as 'count') could be un-initialized, > and lead to memory corruption. Just my 2c. CJ | You must be looking at different code. There is no uninitialized variable. The patched code looks like: drivers/net/wireless/ath/ath11k/mac.c 3520 static void ath11k_mac_setup_he_cap(struct ath11k *ar, 3521 struct ath11k_pdev_cap *cap) 3522 { 3523 struct ieee80211_supported_band *band; 3524 int count; 3525 3526 if (cap->supported_bands & WMI_HOST_WLAN_2G_CAP) { 3527 count = ath11k_mac_copy_he_cap(ar, cap, 3528 ar->mac.iftype[NL80211_BAND_2GHZ], 3529 NL80211_BAND_2GHZ); 3530 band = &ar->mac.sbands[NL80211_BAND_2GHZ]; 3531 band->iftype_data = ar->mac.iftype[NL80211_BAND_2GHZ]; 3532 band->n_iftype_data = count; 3533 } 3534 3535 if (cap->supported_bands & WMI_HOST_WLAN_5G_CAP) { 3536 count = ath11k_mac_copy_he_cap(ar, cap, 3537 ar->mac.iftype[NL80211_BAND_5GHZ], 3538 NL80211_BAND_5GHZ); 3539 band = &ar->mac.sbands[NL80211_BAND_5GHZ]; 3540 band->iftype_data = ar->mac.iftype[NL80211_BAND_5GHZ]; 3541 band->n_iftype_data = count; 3542 } 3543 } regards, dan carpenter