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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 58993C433E4 for ; Thu, 23 Jul 2020 22:12:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CBCB20768 for ; Thu, 23 Jul 2020 22:12:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726901AbgGWWL7 (ORCPT ); Thu, 23 Jul 2020 18:11:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726501AbgGWWL7 (ORCPT ); Thu, 23 Jul 2020 18:11:59 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A7A2C0619D3; Thu, 23 Jul 2020 15:11:59 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id A80C611E48C62; Thu, 23 Jul 2020 14:55:13 -0700 (PDT) Date: Thu, 23 Jul 2020 15:11:58 -0700 (PDT) Message-Id: <20200723.151158.2190104866687627036.davem@davemloft.net> To: madhuparnabhowmik10@gmail.com Cc: isdn@linux-pingi.de, arnd@arndb.de, gregkh@linuxfoundation.org, edumazet@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, andrianov@ispras.ru, ldv-project@linuxtesting.org Subject: Re: [PATCH] drivers: isdn: capi: Fix data-race bug From: David Miller In-Reply-To: <20200722172329.16727-1-madhuparnabhowmik10@gmail.com> References: <20200722172329.16727-1-madhuparnabhowmik10@gmail.com> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 23 Jul 2020 14:55:14 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: madhuparnabhowmik10@gmail.com Date: Wed, 22 Jul 2020 22:53:29 +0530 > From: Madhuparna Bhowmik > > In capi_init(), after register_chrdev() the file operation callbacks > can be called. However capinc_tty_init() is called later. > Since capiminors and capinc_tty_driver are initialized in > capinc_tty_init(), their initialization can race with their usage > in various callbacks like in capi_release(). > > Therefore, call capinc_tty_init() before register_chrdev to avoid > such race conditions. > > Found by Linux Driver Verification project (linuxtesting.org). > > Signed-off-by: Madhuparna Bhowmik I agree with Arnd that this just exchanges one set of problems for another.