From patchwork Tue Mar 10 12:37:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 229546 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 96D50C10F27 for ; Tue, 10 Mar 2020 13:24:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AA5B208E4 for ; Tue, 10 Mar 2020 13:24:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583846675; bh=Xvrs5Tl05cV7m4ac4tT9EVzboSu3Qc+AUWzumDZp8DI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Qx53PkMYznq2/sXxh5qkRqYPWi2/kdUv9cASn+jbWs6bQUC9GvCWCd0mLHCLC4HgL gqqxl1KyG/NOUvjWfhWkj3c/HRPHkOupUaycJ1cXBzfxdCYi9z8EFtInUdyVIFiSh7 +iMupXntVzzilk4qo5cznoDmXmCaz1Y4XRuLbwlg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729974AbgCJM7A (ORCPT ); Tue, 10 Mar 2020 08:59:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:39276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729764AbgCJM67 (ORCPT ); Tue, 10 Mar 2020 08:58:59 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 D059C2468F; Tue, 10 Mar 2020 12:58:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845139; bh=Xvrs5Tl05cV7m4ac4tT9EVzboSu3Qc+AUWzumDZp8DI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V9DVSuiWCFzMEkEHgsVDBCURtfEOxLaUOhu6b5iGgKEHkdSOZNRMB/XF2/ST0aPNy wcRT6jZ5AdT2BQXQQzc/hNVyrllaZ8QO9PyKLlumtOUq2IXcHFYMSIMd4WWm3nAjKB ORbGyPCzJRgmRGpfVekStVOaUbPZtYH+SIVE4br0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Cornelia Huck , Christian Borntraeger , Vasily Averin , Vasily Gorbik , Sasha Levin Subject: [PATCH 5.5 038/189] s390/cio: cio_ignore_proc_seq_next should increase position index Date: Tue, 10 Mar 2020 13:37:55 +0100 Message-Id: <20200310123643.334202771@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310123639.608886314@linuxfoundation.org> References: <20200310123639.608886314@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 [ Upstream commit 8b101a5e14f2161869636ff9cb4907b7749dc0c2 ] if seq_file .next fuction does not change position index, read after some lseek can generate unexpected output. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283 Link: https://lore.kernel.org/r/d44c53a7-9bc1-15c7-6d4a-0c10cb9dffce@virtuozzo.com Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger Signed-off-by: Vasily Averin Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin --- drivers/s390/cio/blacklist.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/s390/cio/blacklist.c b/drivers/s390/cio/blacklist.c index 2a3f874a21d54..9cebff8e8d740 100644 --- a/drivers/s390/cio/blacklist.c +++ b/drivers/s390/cio/blacklist.c @@ -303,8 +303,10 @@ static void * cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset) { struct ccwdev_iter *iter; + loff_t p = *offset; - if (*offset >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1)) + (*offset)++; + if (p >= (__MAX_SUBCHANNEL + 1) * (__MAX_SSID + 1)) return NULL; iter = it; if (iter->devno == __MAX_SUBCHANNEL) { @@ -314,7 +316,6 @@ cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset) return NULL; } else iter->devno++; - (*offset)++; return iter; }