From patchwork Tue Feb 2 13:38:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 376060 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, URIBL_RED,USER_AGENT_GIT 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 520EEC433DB for ; Tue, 2 Feb 2021 17:21:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24A2664F49 for ; Tue, 2 Feb 2021 17:21:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236274AbhBBRVD (ORCPT ); Tue, 2 Feb 2021 12:21:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:49664 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234252AbhBBOOy (ORCPT ); Tue, 2 Feb 2021 09:14:54 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6A65A64FBD; Tue, 2 Feb 2021 13:53:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612274013; bh=OwOgk+5l5C14L3DgTbWLuH1iGvXtOX8bUN7c/SbjFCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zhg82GoYU6W4TWx1Ta+d2XqZ/maKRrn4PW/i+gxHpIs4tWs5w3x78o6xX5dmB92FY 9e8MK34r1orisCnoNXJf+XZehu0XMr56OPLAiPuxvBcdP2m2jpz1hKm25cBk/6dObZ Tbic8Ao5atgvcPEr+gWGgZoPud+Co4tcvjzME0VQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+444248c79e117bc99f46@syzkaller.appspotmail.com, syzbot+8b2a88a09653d4084179@syzkaller.appspotmail.com, Johannes Berg Subject: [PATCH 4.19 08/37] wext: fix NULL-ptr-dereference with cfg80211s lack of commit() Date: Tue, 2 Feb 2021 14:38:51 +0100 Message-Id: <20210202132943.241948392@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210202132942.915040339@linuxfoundation.org> References: <20210202132942.915040339@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Johannes Berg commit 5122565188bae59d507d90a9a9fd2fd6107f4439 upstream. Since cfg80211 doesn't implement commit, we never really cared about that code there (and it's configured out w/o CONFIG_WIRELESS_EXT). After all, since it has no commit, it shouldn't return -EIWCOMMIT to indicate commit is needed. However, EIWCOMMIT is actually an alias for EINPROGRESS, which _can_ happen if e.g. we try to change the frequency but we're already in the process of connecting to some network, and drivers could return that value (or even cfg80211 itself might). This then causes us to crash because dev->wireless_handlers is NULL but we try to check dev->wireless_handlers->standard[0]. Fix this by also checking dev->wireless_handlers. Also simplify the code a little bit. Cc: stable@vger.kernel.org Reported-by: syzbot+444248c79e117bc99f46@syzkaller.appspotmail.com Reported-by: syzbot+8b2a88a09653d4084179@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20210121171621.2076e4a37d5a.I5d9c72220fe7bb133fb718751da0180a57ecba4e@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/wireless/wext-core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -896,8 +896,9 @@ out: int call_commit_handler(struct net_device *dev) { #ifdef CONFIG_WIRELESS_EXT - if ((netif_running(dev)) && - (dev->wireless_handlers->standard[0] != NULL)) + if (netif_running(dev) && + dev->wireless_handlers && + dev->wireless_handlers->standard[0]) /* Call the commit handler on the driver */ return dev->wireless_handlers->standard[0](dev, NULL, NULL, NULL);