From patchwork Tue Feb 2 13:38:22 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: 375213 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, USER_AGENT_GIT 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 60691C433E6 for ; Tue, 2 Feb 2021 18:15:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30DF764F96 for ; Tue, 2 Feb 2021 18:15:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233762AbhBBSPC (ORCPT ); Tue, 2 Feb 2021 13:15:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:48170 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233755AbhBBOGr (ORCPT ); Tue, 2 Feb 2021 09:06:47 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4058364F8A; Tue, 2 Feb 2021 13:49:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612273760; bh=RJDCFXImZvgvdSzSWkgwTrPDoj3s9Vwunh9MmD1RkYo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1OccwstRYmS+2M1YokQ+hrbdaglSfJA2fLuYy9RF+z0HRGyzwlf/BUyJf5BIAHXGy rJP6xohQGbxkfqcOP7ONYbLi0XTeCDeyu3g74BWG/HwvhC6yVhhNkaNabYR4qYHT8n IXoY8O6U8uxFKWbD9MjZ84mPH57/1kSMxB9B02io= 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 4.4 02/28] wext: fix NULL-ptr-dereference with cfg80211s lack of commit() Date: Tue, 2 Feb 2021 14:38:22 +0100 Message-Id: <20210202132941.292369092@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210202132941.180062901@linuxfoundation.org> References: <20210202132941.180062901@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 @@ -895,8 +895,9 @@ 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);