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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 CEB64C7618B for ; Wed, 24 Jul 2019 12:40:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B103F229ED for ; Wed, 24 Jul 2019 12:40:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726574AbfGXMkl (ORCPT ); Wed, 24 Jul 2019 08:40:41 -0400 Received: from s3.sipsolutions.net ([144.76.43.62]:52926 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725776AbfGXMkk (ORCPT ); Wed, 24 Jul 2019 08:40:40 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hqGZO-0005pu-SF; Wed, 24 Jul 2019 14:40:34 +0200 Message-ID: <127c411cc06e04b61220a571f5332b9155c69f77.camel@sipsolutions.net> Subject: Re: [PATCH 1/2] net: mac80211: Fix possible null-pointer dereferences in ieee80211_setup_sdata() From: Johannes Berg To: Jia-Ju Bai , davem@davemloft.net Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 24 Jul 2019 14:40:33 +0200 In-Reply-To: <20190724123623.10093-1-baijiaju1990@gmail.com> (sfid-20190724_143632_658051_4FE62E07) References: <20190724123623.10093-1-baijiaju1990@gmail.com> (sfid-20190724_143632_658051_4FE62E07) Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 2019-07-24 at 20:36 +0800, Jia-Ju Bai wrote: > In ieee80211_setup_sdata(), there is an if statement on line 1410 to > check whether sdata->dev is NULL: > if (sdata->dev) > > When sdata->dev is NULL, it is used on lines 1458 and 1459: > sdata->dev->type = ARPHRD_IEEE80211_RADIOTAP; > sdata->dev->netdev_ops = &ieee80211_monitorif_ops; > > Thus, possible null-pointer dereferences may occur. No, this cannot happen, monitor interfaces (NL80211_IFTYPE_MONITOR) must have a valid ->dev, only P2P device and NAN might not. johannes