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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11134C38A02 for ; Mon, 31 Oct 2022 06:49:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229636AbiJaGta (ORCPT ); Mon, 31 Oct 2022 02:49:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229642AbiJaGt3 (ORCPT ); Mon, 31 Oct 2022 02:49:29 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5F51EBCB4 for ; Sun, 30 Oct 2022 23:49:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 1F295B81147 for ; Mon, 31 Oct 2022 06:49:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C7A0C433D6; Mon, 31 Oct 2022 06:49:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1667198965; bh=F7NS55PXNDG2dxy18LS7uM5j0bh8v0Yl1a/TTeUe32o=; h=Subject:To:Cc:From:Date:From; b=s3qdJ5PJmJapby3/KlmwvoZOIDwIEEQXQhZA5mr41lT7Dz9KBHXAZvhkQUXC5K8T0 69T5bNZiTcZcshLVQPxUUv3dSAdsAjjTM/9HepClATxQ3HFCOqtW71zJwKT5hMqLI+ Gm9WLffdCHhGuVHbpm9T0LJdUALb5BR+cyypZ0NQ= Subject: FAILED: patch "[PATCH] s390/cio: fix out-of-bounds access on cio_ignore free" failed to apply to 5.15-stable tree To: oberpar@linux.ibm.com, egorenar@linux.ibm.com, gor@linux.ibm.com, stable@vger.kernel.org, vneethv@linux.ibm.com Cc: From: Date: Mon, 31 Oct 2022 07:50:21 +0100 Message-ID: <16671990212509@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . Possible dependencies: 1b6074112742 ("s390/cio: fix out-of-bounds access on cio_ignore free") 0c3812c347bf ("s390/cio: derive cdev information only for IO-subchannels") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1b6074112742f65ece71b0f299ca5a6a887d2db6 Mon Sep 17 00:00:00 2001 From: Peter Oberparleiter Date: Fri, 14 Oct 2022 12:24:58 +0200 Subject: [PATCH] s390/cio: fix out-of-bounds access on cio_ignore free The channel-subsystem-driver scans for newly available devices whenever device-IDs are removed from the cio_ignore list using a command such as: echo free >/proc/cio_ignore Since an I/O device scan might interfer with running I/Os, commit 172da89ed0ea ("s390/cio: avoid excessive path-verification requests") introduced an optimization to exclude online devices from the scan. The newly added check for online devices incorrectly assumes that an I/O-subchannel's drvdata points to a struct io_subchannel_private. For devices that are bound to a non-default I/O subchannel driver, such as the vfio_ccw driver, this results in an out-of-bounds read access during each scan. Fix this by changing the scan logic to rely on a driver-independent online indication. For this we can use struct subchannel->config.ena, which is the driver's requested subchannel-enabled state. Since I/Os can only be started on enabled subchannels, this matches the intent of the original optimization of not scanning devices where I/O might be running. Fixes: 172da89ed0ea ("s390/cio: avoid excessive path-verification requests") Fixes: 0c3812c347bf ("s390/cio: derive cdev information only for IO-subchannels") Cc: # v5.15 Reported-by: Alexander Egorenkov Reviewed-by: Vineeth Vijayan Signed-off-by: Peter Oberparleiter Signed-off-by: Vasily Gorbik diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index 913b6ddd040b..c7db95398500 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -753,13 +753,9 @@ static int __unset_online(struct device *dev, void *data) { struct idset *set = data; struct subchannel *sch = to_subchannel(dev); - struct ccw_device *cdev; - if (sch->st == SUBCHANNEL_TYPE_IO) { - cdev = sch_get_cdev(sch); - if (cdev && cdev->online) - idset_sch_del(set, sch->schid); - } + if (sch->st == SUBCHANNEL_TYPE_IO && sch->config.ena) + idset_sch_del(set, sch->schid); return 0; }