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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 6431FC3F2D2 for ; Tue, 3 Mar 2020 02:51:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 276352166E for ; Tue, 3 Mar 2020 02:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583203903; bh=A//OTV3+t80o4DfPxG+5T9Nazx04EEHsGGsu+omI/XM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kG5VUOm0ueGlQOtXcz+Xvixj4jFTYq8NLIPX5q4QNMnenJG6Lq6FA+GJWoZVKgTG2 rI22XKDDHZBlG+4A7DZWP1EIaOKJy3rj+1tCaO0KgQKATX3iMZ2gbwj6EVTvMGeUcV 6emUiwraskhG5r7/EO9eeVu54n8kWUPnkH2qUrN4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728558AbgCCCvl (ORCPT ); Mon, 2 Mar 2020 21:51:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:47118 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729136AbgCCCuU (ORCPT ); Mon, 2 Mar 2020 21:50:20 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7D12E246EA; Tue, 3 Mar 2020 02:50:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583203819; bh=A//OTV3+t80o4DfPxG+5T9Nazx04EEHsGGsu+omI/XM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NwFkSFX1YVOCb8ua/bW0hlvRG96GBVn+NFLUgn32H4ILJLvMmBT/lLcKt8mUWLzmm nJPfWIDxCbJrocI6eW/xT2Xp0APbyTY4OUMtb0fJY0RBOIe/uQ9yQ9p7zAyb4xXqlA F5JD4OVf8Wu7i8bU/81uWGBGgfi1CvCZO1in4fh8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vasily Averin , Cornelia Huck , Christian Borntraeger , Vasily Gorbik , Sasha Levin , linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 12/13] s390/cio: cio_ignore_proc_seq_next should increase position index Date: Mon, 2 Mar 2020 21:50:01 -0500 Message-Id: <20200303025002.10600-12-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200303025002.10600-1-sashal@kernel.org> References: <20200303025002.10600-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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