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 EFB98C433EF for ; Thu, 7 Jul 2022 07:34:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231879AbiGGHeS (ORCPT ); Thu, 7 Jul 2022 03:34:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230211AbiGGHeO (ORCPT ); Thu, 7 Jul 2022 03:34:14 -0400 Received: from mail-ej1-f53.google.com (mail-ej1-f53.google.com [209.85.218.53]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECDBF27CEB; Thu, 7 Jul 2022 00:34:13 -0700 (PDT) Received: by mail-ej1-f53.google.com with SMTP id d2so30958990ejy.1; Thu, 07 Jul 2022 00:34:13 -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=k8tCCPWhXFVw0Grisrt5wFNoaTf/P1qQq3zFo+9VxAU=; b=rWXLdaf2OeP5L+OqvLqX7kccZvzNu/Sbm/Z5qqMCsQnFaDuAilP78E3VnRA3kTK2ce KeJT7AVKnDcBBdFgZsCLpMsHc34MfuO/YIoXzkooM/whrNtlHPXxyoP1nn4zfl8b7E4L RPTMbicDIB3nGPOc6MkjpzDi4YGasZhibkOWIh6iKGIQ36g7Nkx14ooqicAqgeS0vWHj 3/J7OscqtBM5OSAk4+zmPSYP/vs5tYa1tnfxZteDQmlANeV1hwFLyo+Uil2Dj+dYk6j8 CvviQerZP8lg6Yd4oVMPB3asgZhuRR1YaiBJU6b4234xfQM/42vcHHOmeJWA1hxmOHqa ynCQ== X-Gm-Message-State: AJIora/5uptEBwd6GXpSYGJLFG+MWL02JX+QaqTjrIhoEWrJhRKpwY9q YMyL+6W4Pi6aR1fAeI15HBmkZRVJyTk= X-Google-Smtp-Source: AGRyM1u/+uQThAQr5NmhyoCOv3AsBtJTeHBUK7T9xKARuWT3qKFBeJ52TvhvRE15BiwRm4rk1JYfkA== X-Received: by 2002:a17:907:16a2:b0:726:abbc:69bf with SMTP id hc34-20020a17090716a200b00726abbc69bfmr42564140ejc.363.1657179252575; Thu, 07 Jul 2022 00:34:12 -0700 (PDT) Received: from ?IPV6:2a0b:e7c0:0:107::49? ([2a0b:e7c0:0:107::49]) by smtp.gmail.com with ESMTPSA id cn22-20020a0564020cb600b0043a896048basm3299207edb.85.2022.07.07.00.34.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 07 Jul 2022 00:34:12 -0700 (PDT) Message-ID: <17759c4b-5858-12bb-4beb-c4a1d58c89ae@kernel.org> Date: Thu, 7 Jul 2022 09:34:11 +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: "Starke, Daniel" , "linux-serial@vger.kernel.org" , "gregkh@linuxfoundation.org" Cc: "linux-kernel@vger.kernel.org" References: From: Jiri Slaby In-Reply-To: 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 07. 07. 22, 9:00, Starke, Daniel wrote: >>> @@ -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. > > I can remove this check if it is redundant. Should I? Sure as it makes little sense anyway. Even if gsm was non-NULL here, the backing disc_data would be freed on the accesses further. thanks, -- js suse labs