From patchwork Thu Apr 14 13:09:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 562579 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 D0937C433F5 for ; Thu, 14 Apr 2022 13:20:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244068AbiDNNXO (ORCPT ); Thu, 14 Apr 2022 09:23:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244131AbiDNNWb (ORCPT ); Thu, 14 Apr 2022 09:22:31 -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 5BDC9986C9; Thu, 14 Apr 2022 06:17:47 -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 E236AB82985; Thu, 14 Apr 2022 13:17:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 336C2C385A1; Thu, 14 Apr 2022 13:17:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649942264; bh=Q4wNoLp5L+7nNfRO8LA//Pno1XBtwFxiTZA5cUzfUFc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0kxniU3Iz+gQRQpKUfYhiiq/w5Bd+bS+tO0ZKWZyR1WtEpK/EdqOr+BsDVDVa9Hsu OKBhyh64iw6epZ/EnejFTas7zQ0qNmJLtmHOgPuddwKzol8/Ya6//8xqAMpJojR/RB h23SI73ob8KgbBj6k9eAgkjnLyeuvpstYWELdkZk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hannes Reinecke , Bart Van Assche , Eric Biggers , Christoph Hellwig , Jens Axboe , Sasha Levin Subject: [PATCH 4.19 074/338] block: dont delete queue kobject before its children Date: Thu, 14 Apr 2022 15:09:37 +0200 Message-Id: <20220414110841.006123971@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110838.883074566@linuxfoundation.org> References: <20220414110838.883074566@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers [ Upstream commit 0f69288253e9fc7c495047720e523b9f1aba5712 ] kobjects aren't supposed to be deleted before their child kobjects are deleted. Apparently this is usually benign; however, a WARN will be triggered if one of the child kobjects has a named attribute group: sysfs group 'modes' not found for kobject 'crypto' WARNING: CPU: 0 PID: 1 at fs/sysfs/group.c:278 sysfs_remove_group+0x72/0x80 ... Call Trace: sysfs_remove_groups+0x29/0x40 fs/sysfs/group.c:312 __kobject_del+0x20/0x80 lib/kobject.c:611 kobject_cleanup+0xa4/0x140 lib/kobject.c:696 kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x53/0x70 lib/kobject.c:753 blk_crypto_sysfs_unregister+0x10/0x20 block/blk-crypto-sysfs.c:159 blk_unregister_queue+0xb0/0x110 block/blk-sysfs.c:962 del_gendisk+0x117/0x250 block/genhd.c:610 Fix this by moving the kobject_del() and the corresponding kobject_uevent() to the correct place. Fixes: 2c2086afc2b8 ("block: Protect less code with sysfs_lock in blk_{un,}register_queue()") Reviewed-by: Hannes Reinecke Reviewed-by: Greg Kroah-Hartman Reviewed-by: Bart Van Assche Signed-off-by: Eric Biggers Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220124215938.2769-3-ebiggers@kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-sysfs.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 07494deb1a26..67836f212e2d 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -1002,9 +1002,6 @@ void blk_unregister_queue(struct gendisk *disk) */ if (q->mq_ops) blk_mq_unregister_dev(disk_to_dev(disk), q); - - kobject_uevent(&q->kobj, KOBJ_REMOVE); - kobject_del(&q->kobj); blk_trace_remove_sysfs(disk_to_dev(disk)); mutex_lock(&q->sysfs_lock); @@ -1015,6 +1012,11 @@ void blk_unregister_queue(struct gendisk *disk) if (q->request_fn || q->elevator) elv_unregister_queue(q); mutex_unlock(&q->sysfs_lock); + + /* Now that we've deleted all child objects, we can delete the queue. */ + kobject_uevent(&q->kobj, KOBJ_REMOVE); + kobject_del(&q->kobj); + mutex_unlock(&q->sysfs_dir_lock); kobject_put(&disk_to_dev(disk)->kobj);