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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 72A87C433E1 for ; Mon, 17 Aug 2020 18:30:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B2432053B for ; Mon, 17 Aug 2020 18:30:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597689034; bh=drg9k6fAr4o4ZaB/KVXQaJmhieDdCk/mTFHnx7qh7P0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xMJWEH9/kgEbtYx4Lb3k+G9amzy1xlJI/IDOen92g+fiCNhwGAvQVLVjW8atpmwHQ 6DURvUU1WcaBf30QzbOCf9edDWlWSaf8FXVHgLJUYKLSRYfnyNctHQ55FDAaDZ0yc9 F+I9n5o4QYk3Hs+laxOpeFJRavOFxMk0cn/wlRUw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391063AbgHQSac (ORCPT ); Mon, 17 Aug 2020 14:30:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:48692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388151AbgHQQBq (ORCPT ); Mon, 17 Aug 2020 12:01:46 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E4B8820888; Mon, 17 Aug 2020 16:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597680093; bh=drg9k6fAr4o4ZaB/KVXQaJmhieDdCk/mTFHnx7qh7P0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Inzvtp6M2L92mzD0oKo3FPCDv7eT3wllShqtmQGwXooVhnfVNc93Y1rh+CiHLRGAk rtyoTBdOb2wZYA4l+9Iyd/pX2RqPPOnQhrnzoIQE52hnbtAPGjtd851xXnplXsMLLy DMMwp4zmPhT0O3G5Tnc5VzbP0nS9IqU+lym6sqMA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Luis Chamberlain , Ming Lei , Christoph Hellwig , Jens Axboe , Sasha Levin Subject: [PATCH 5.4 049/270] loop: be paranoid on exit and prevent new additions / removals Date: Mon, 17 Aug 2020 17:14:10 +0200 Message-Id: <20200817143758.221285604@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143755.807583758@linuxfoundation.org> References: <20200817143755.807583758@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Luis Chamberlain [ Upstream commit 200f93377220504c5e56754823e7adfea6037f1a ] Be pedantic on removal as well and hold the mutex. This should prevent uses of addition while we exit. Signed-off-by: Luis Chamberlain Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/loop.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 565e35e69f249..bddbbf5b3dda2 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -2325,6 +2325,8 @@ static void __exit loop_exit(void) range = max_loop ? max_loop << part_shift : 1UL << MINORBITS; + mutex_lock(&loop_ctl_mutex); + idr_for_each(&loop_index_idr, &loop_exit_cb, NULL); idr_destroy(&loop_index_idr); @@ -2332,6 +2334,8 @@ static void __exit loop_exit(void) unregister_blkdev(LOOP_MAJOR, "loop"); misc_deregister(&loop_misc); + + mutex_unlock(&loop_ctl_mutex); } module_init(loop_init); -- 2.25.1