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 26890C4332F for ; Thu, 15 Dec 2022 06:50:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229460AbiLOGux (ORCPT ); Thu, 15 Dec 2022 01:50:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229655AbiLOGup (ORCPT ); Thu, 15 Dec 2022 01:50:45 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FFDB21E33; Wed, 14 Dec 2022 22:50:43 -0800 (PST) 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 D84F4B81AD3; Thu, 15 Dec 2022 06:50:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3612CC433F2; Thu, 15 Dec 2022 06:50:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1671087040; bh=dsffucc6I2sU3ocPccR5Wt4nUWd9vSTjx8+hyd+0RWQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DLm5tHEZp1xiGgjKyWDc+mWbcd5f6p2OlvsnREv2115mQ8NI9eca8UpCJ/F9S+bfN wuARYqKkjrLkNOlRqTUcvvfj+U9SeIkxGqHC72Qm2a1GtTZYLWXq2D/LpQ10Gw9DDD 61WkHnvIoJ1xqk4TdMFQu1xKHfOwpnegDxaDCSvM= Date: Thu, 15 Dec 2022 07:50:30 +0100 From: Greg Kroah-Hartman To: Ming Lei Cc: stable@vger.kernel.org, Jens Axboe , linux-block@vger.kernel.org, Shiwei Cui , Christoph Hellwig , Jan Kara Subject: Re: [PATCH stable 4.9.y] block: unhash blkdev part inode when the part is deleted Message-ID: References: <20221213071655.1197875-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221213071655.1197875-1-ming.lei@redhat.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, Dec 13, 2022 at 03:16:55PM +0800, Ming Lei wrote: > v5.11 changes the blkdev lookup mechanism completely since commit > 22ae8ce8b892 ("block: simplify bdev/disk lookup in blkdev_get"), > and small part of the change is to unhash part bdev inode when > deleting partition. Turns out this kind of change does fix one > nasty issue in case of BLOCK_EXT_MAJOR: > > 1) when one partition is deleted & closed, disk_put_part() is always > called before bdput(bdev), see blkdev_put(); so the part's devt can > be freed & re-used before the inode is dropped > > 2) then new partition with same devt can be created just before the > inode in 1) is dropped, then the old inode/bdev structurein 1) is > re-used for this new partition, this way causes use-after-free and > kernel panic. > > It isn't possible to backport the whole big patchset of "merge struct > block_device and struct hd_struct v4" for addressing this issue. > > https://lore.kernel.org/linux-block/20201128161510.347752-1-hch@lst.de/ > > So fixes it by unhashing part bdev in delete_partition(), and this way > is actually aligned with v5.11+'s behavior. > > Backported from the following 5.10.y commit: > > 5f2f77560591 ("block: unhash blkdev part inode when the part is deleted") > > Reported-by: Shiwei Cui > Tested-by: Shiwei Cui > Cc: Christoph Hellwig > Cc: Jan Kara > Signed-off-by: Ming Lei > --- > block/partition-generic.c | 6 ++++++ > 1 file changed, 6 insertions(+) All now queued up, thanks! greg k-h