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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22EAFC433EF for ; Tue, 9 Nov 2021 17:33:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CD5761251 for ; Tue, 9 Nov 2021 17:33:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241147AbhKIRgF (ORCPT ); Tue, 9 Nov 2021 12:36:05 -0500 Received: from mail-ed1-f45.google.com ([209.85.208.45]:44721 "EHLO mail-ed1-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241098AbhKIRgD (ORCPT ); Tue, 9 Nov 2021 12:36:03 -0500 Received: by mail-ed1-f45.google.com with SMTP id j21so79475724edt.11 for ; Tue, 09 Nov 2021 09:33:17 -0800 (PST) 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=TvDol0kBPfNRwWgilmXm6cYollzM35nH7ADS6bmCDOM=; b=cgxNGc5KbR7tx74VoBR1pzNHMlvQt4JmIa3boeKoMc9fsUhRicGLvZhlnU8TYBBrYp oATfuZBfx0DRtH5aGCwE9iUfSKqyKijuhrhMm8M+5jJ0SEaD+sp4Q6SP1GIo6i0V7Z1K TDcwqi5Ga5CiWkzE2/0pHJJra1iWEqUOwDa8R8SDSm2p5vr/EMechIYBffHE8fz66NLI 9UQLgPAKu84J3mTEuBnwbERD9ibors+igEL01vXSYFj7W48LBMGmPv7GIb61AJnZHSVM EWTXcU2G4EDb90kZGLLIG7EIZbSM/N4zTbmRk4qKzg/KSjOiHB6m+b3GCKX0ELmtwY12 jivQ== X-Gm-Message-State: AOAM530xGkQZEJRFMOaEHSQOvZTt3VmU+B0yUIm2FZTskUHsQ8z1Z8X1 inwRMBf3HgvIFOgGqTv95ccvePVbkL8= X-Google-Smtp-Source: ABdhPJypIaVIKUSgSQiOlr5ivJOEud4gdilaXvtsRPJMu7hwA+XMimaRZCxMy5wNyZ5sPYQPfzljAw== X-Received: by 2002:a17:906:961a:: with SMTP id s26mr11426739ejx.494.1636479196493; Tue, 09 Nov 2021 09:33:16 -0800 (PST) Received: from [192.168.1.49] (185-219-167-24-static.vivo.cz. [185.219.167.24]) by smtp.gmail.com with ESMTPSA id c11sm4490483ede.8.2021.11.09.09.33.15 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 09 Nov 2021 09:33:15 -0800 (PST) Message-ID: <8e7d4214-01b8-d1a7-adaf-f2135cb6431a@kernel.org> Date: Tue, 9 Nov 2021 18:33:14 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.2.1 Subject: Re: [PATCH] tty: n_gsm: add missing tty_kref_put Content-Language: en-US To: Pavel Skripkin , gregkh@linuxfoundation.org, hdanton@sina.com Cc: linux-kernel@vger.kernel.org References: <20211109103930.27494-1-paskripkin@gmail.com> From: Jiri Slaby In-Reply-To: <20211109103930.27494-1-paskripkin@gmail.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 09. 11. 21, 11:39, Pavel Skripkin wrote: > My local syzbot instance hit memory leak in gsmld_attach_gsm(). The > reproducer injects allocation failure in tty_register_device(). After > this error only previous tty_register_device() calls unwinded, but not > tty_kref_get(). > > It leads to tty_struct leak, because ->close() won't be called in case > of ->open() failure and nothing puts tty reference. I don't have time to check the n_gsm case now (like: are you talking about tty->open/close or file_ops->open/close -- they behave differently), but tty definitely calls close even if open fails. > Fixes: 0a360e8b65d6 ("tty: n_gsm: check error while registering tty devices") > Signed-off-by: Pavel Skripkin > --- > drivers/tty/n_gsm.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c > index 1d92d2a84889..1cc3aec17d2d 100644 > --- a/drivers/tty/n_gsm.c > +++ b/drivers/tty/n_gsm.c > @@ -2394,6 +2394,8 @@ static int gsmld_attach_gsm(struct tty_struct *tty, struct gsm_mux *gsm) > for (i--; i >= 1; i--) > tty_unregister_device(gsm_tty_driver, > base + i); > + > + tty_kref_put(gsm->tty); > return PTR_ERR(dev); > } > } > -- js suse labs