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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AD7DC433EF for ; Thu, 7 Jul 2022 06:48:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234626AbiGGGsn (ORCPT ); Thu, 7 Jul 2022 02:48:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233783AbiGGGsk (ORCPT ); Thu, 7 Jul 2022 02:48:40 -0400 Received: from mail-ej1-f48.google.com (mail-ej1-f48.google.com [209.85.218.48]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B307118B24; Wed, 6 Jul 2022 23:48:38 -0700 (PDT) Received: by mail-ej1-f48.google.com with SMTP id dn9so25449694ejc.7; Wed, 06 Jul 2022 23:48:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=90jJy+ca1WJWTmf30QTwkp6Rg+7I6b/A/6FAp+w4mRQ=; b=pEmsXxO+cyClKeyTCEEcHYDpMai69VhIvw3zM1LlD/Az3dbOI/DmC7uSojytNlHPUH 3oSTbtwvADvIjq+2JcarA2gxCQ8/mKFQdN/pgRHnl8+2nTFluDGb4zIWF2cCw/Onrym4 HbhFB4PZHhh+8aENye+uGHSA7yzX1FTMP4CJg6HzsCmioG78aQcWns0WnGnzRnw79ctv sGsfzhu12kManlrE+ktuL7J0qPPd/LMCp8hXnoykaPq0DCfaQ6TsAb14IMWVr6dFawi2 sYGu3pItXGITd4WaSsJqndv896nZpx5Z3fJ8NSulAypmBq+dTS+FpYHjm88u7uTR9NCs ZRJQ== X-Gm-Message-State: AJIora/T6en+/fy+GRwbcim6C12mjT2RUUZS6wefP08tP8fwZJNQ5yMy 85adtvfX0ecEMCwVwZxxid0= X-Google-Smtp-Source: AGRyM1uTViCcG7u/rZveiGTrA3aqCtDAbjrXBZb5bEcOtW0SE1Ld4uSXhqAn/3xhV+vQU49DQrkKpA== X-Received: by 2002:a17:906:8442:b0:72a:8b2b:c5c5 with SMTP id e2-20020a170906844200b0072a8b2bc5c5mr30490909ejy.691.1657176517140; Wed, 06 Jul 2022 23:48:37 -0700 (PDT) Received: from ?IPV6:2a0b:e7c0:0:107::49? ([2a0b:e7c0:0:107::49]) by smtp.gmail.com with ESMTPSA id h7-20020a1709070b0700b00711d8696de9sm18368673ejl.70.2022.07.06.23.48.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 06 Jul 2022 23:48:36 -0700 (PDT) Message-ID: <1c605fa7-dddf-fb9d-0656-286bb6830d36@kernel.org> Date: Thu, 7 Jul 2022 08:48:35 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH 4/4] tty: n_gsm: fix missing corner cases in gsmld_poll() Content-Language: en-US To: "D. Starke" , linux-serial@vger.kernel.org, gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org References: <20220706054452.3663-1-daniel.starke@siemens.com> <20220706054452.3663-4-daniel.starke@siemens.com> From: Jiri Slaby In-Reply-To: <20220706054452.3663-4-daniel.starke@siemens.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06. 07. 22, 7:44, D. Starke wrote: > From: Daniel Starke > > gsmld_poll() currently fails to handle some corner cases correctly: > - tty ldisc association lost > - remote party closed the associated tty > > Add the missing checks and map those to EPOLLHUP. > Reorder the checks to group them by their reaction. > > Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") > Signed-off-by: Daniel Starke > --- > drivers/tty/n_gsm.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > Based on tty-testing. > > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c > index 51447ccccbab..47566bd2ed6e 100644 > --- a/drivers/tty/n_gsm.c > +++ b/drivers/tty/n_gsm.c > @@ -3051,14 +3051,20 @@ static __poll_t gsmld_poll(struct tty_struct *tty, struct file *file, > __poll_t mask = 0; > struct gsm_mux *gsm = tty->disc_data; > > + if (!gsm) > + return EPOLLHUP; Hmm, how can this happen? It's a tty bug if it calls ld ops after NULLing disc_data. thanks, -- js suse labs