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 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,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 DAEE0C10F27 for ; Tue, 10 Mar 2020 12:46:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3B1D24691 for ; Tue, 10 Mar 2020 12:46:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583844392; bh=A//OTV3+t80o4DfPxG+5T9Nazx04EEHsGGsu+omI/XM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wLUKZMpev16ljVD1iGgtbEXvb3BxmYJ7Ej+MbRylYDN+U4WUhDw4VzVI6HjxxD5pe wkOco1Ca/4D4dcxxxSxbFnhTnFf1cJrjiJxeJdDqIyh1SvN8Omn/FVlxZVTK5bvyP3 wKHWWmqIbKbhFbeEXS14STMHGYYPbXZB8gtksCe4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727360AbgCJMqb (ORCPT ); Tue, 10 Mar 2020 08:46:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:49692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728020AbgCJMq1 (ORCPT ); Tue, 10 Mar 2020 08:46:27 -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 E46DD2468D; Tue, 10 Mar 2020 12:46:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583844386; bh=A//OTV3+t80o4DfPxG+5T9Nazx04EEHsGGsu+omI/XM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OGRsfUXlizfVjX6q4EdMlMUkgJeTRCDOvzjEdIQ91tTVNf9/hZf/KpbXHD3V1awT7 2Cs+JIASsxwCFBhU2uLHw8euzqNStoH5rs9xAfaeAANkXkwsOWQMz3Et+B5tixTllS IVN/HNxhd92jhBtG/OoYrXJyksbn01FVrNyhggzg= 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 4.9 61/88] s390/cio: cio_ignore_proc_seq_next should increase position index Date: Tue, 10 Mar 2020 13:39:09 +0100 Message-Id: <20200310123621.642063499@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310123606.543939933@linuxfoundation.org> References: <20200310123606.543939933@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 9082476b51db9..4e9f794176d35 100644 --- a/drivers/s390/cio/blacklist.c +++ b/drivers/s390/cio/blacklist.c @@ -302,8 +302,10 @@ 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) { @@ -313,7 +315,6 @@ cio_ignore_proc_seq_next(struct seq_file *s, void *it, loff_t *offset) return NULL; } else iter->devno++; - (*offset)++; return iter; } -- 2.20.1