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 08D3CC3F2CD for ; Tue, 3 Mar 2020 02:54:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C9ED7217F4 for ; Tue, 3 Mar 2020 02:54:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583204062; bh=Xvrs5Tl05cV7m4ac4tT9EVzboSu3Qc+AUWzumDZp8DI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=yIShcpgwM6gSkFf3MMWPq7O398nI2qRfg9RCGhngk5PS9lxW2n7kSlyvMvgPAslgN 2C4HkTDlI+Cvbi5h8ajEvg6W99reF3zE76RNaKU7+P7ZfBrdwfIQXS5KTPlkeCBbNS F+gx+PFFpFrJvWV1j8aUEp9meMTir6WfxQQDr+d4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728904AbgCCCyV (ORCPT ); Mon, 2 Mar 2020 21:54:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:45568 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728761AbgCCCtV (ORCPT ); Mon, 2 Mar 2020 21:49:21 -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 9D85424684; Tue, 3 Mar 2020 02:49:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583203760; bh=Xvrs5Tl05cV7m4ac4tT9EVzboSu3Qc+AUWzumDZp8DI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GHHSTsqBI6a1YXvmnCrrWSKO+R2CV7MvtU3zgICoikdTVp99kNO6WdawCnQt1hrYV qLfpfv1SvqSIF2Y6S13JlgihDbIUQaBJLo1UOaJ+VylrCQWj1jUD9pZ2GzqrHbCDiq sDh/4Vb3e4DhZGUq0HVqn80/1hK33l6g4/KDyHWI= 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 4.19 22/32] s390/cio: cio_ignore_proc_seq_next should increase position index Date: Mon, 2 Mar 2020 21:48:41 -0500 Message-Id: <20200303024851.10054-22-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200303024851.10054-1-sashal@kernel.org> References: <20200303024851.10054-1-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 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; } -- 2.20.1