From patchwork Mon Feb 10 12:32:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 231642 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 8C12CC352A3 for ; Mon, 10 Feb 2020 13:32:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6610820715 for ; Mon, 10 Feb 2020 13:32:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581341555; bh=sn2gH0G0oELtT8XFpcuSDygN3tH4n+Amn/9fUJWFWFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Mdo2MKrnavHE4t/+Fp5TRjdc6Y2iKEA3UdRL4fccKKHEC2bYLUhW+62n3tmoK5tr9 cWIC3epzc2xEy7yXzBo4SDM3f1n+BC21wY6wb6f6vndF8hieRfXHbJiW2xvnLWtUHO WnzbHlWvMDjCPG4OKQWud1sv6GWyLloOvgzki4lU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728259AbgBJNcb (ORCPT ); Mon, 10 Feb 2020 08:32:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:53592 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728101AbgBJMfq (ORCPT ); Mon, 10 Feb 2020 07:35:46 -0500 Received: from localhost (unknown [209.37.97.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 23CB424676; Mon, 10 Feb 2020 12:35:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581338146; bh=sn2gH0G0oELtT8XFpcuSDygN3tH4n+Amn/9fUJWFWFA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yEdpDtyEOhGsMXKw+yLlNns8wmWTQ3wo+4elSH4hL8SAZyH7EJIkqWsh3oqKKf7sg ON0MtAVsH9y6X5geYeND5kpO/lwnLKHMO6K8OQecuO/ctzJdm9HMNbB6YNOeXk/27n 3wS6oGw9O4UYfhinDl+MD8p9Qg2HAzOec0qYSZU4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable@kernel.org, Vasily Averin , Jan Kara , Theodore Tso Subject: [PATCH 4.19 105/195] jbd2_seq_info_next should increase position index Date: Mon, 10 Feb 2020 04:32:43 -0800 Message-Id: <20200210122315.590513717@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200210122305.731206734@linuxfoundation.org> References: <20200210122305.731206734@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vasily Averin commit 1a8e9cf40c9a6a2e40b1e924b13ed303aeea4418 upstream. if seq_file .next fuction does not change position index, read after some lseek can generate unexpected output. Script below generates endless output $ q=;while read -r r;do echo "$((++q)) $r";done Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/d13805e5-695e-8ac3-b678-26ca2313629f@virtuozzo.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/journal.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1002,6 +1002,7 @@ static void *jbd2_seq_info_start(struct static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos) { + (*pos)++; return NULL; }