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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D33AAC433EF for ; Mon, 25 Oct 2021 02:55:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B169E60F4F for ; Mon, 25 Oct 2021 02:55:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232290AbhJYC50 (ORCPT ); Sun, 24 Oct 2021 22:57:26 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38446 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232280AbhJYC5Z (ORCPT ); Sun, 24 Oct 2021 22:57:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1635130503; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AE0JY6csuXHuv4AM42+KRRY1fWa7BR0iAL/p8wT8I/8=; b=EbdNglyPahV46o18aOQ41jBNu6FBsvov7lQdrlC0AOVpeFdL7AExp//lwllU1Kl6MjCBoh riHmEjYY4K/m4ECVsQztaEZGleArOolBKV9qXlgJoqooJeXL3VYmDRdyJ3U9I2teKcBbt7 8KDx/1eUv2OF+gJ/fgoNtIzySHLC9h4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-373-gh3LXyuHM9el8AtAnQEg4Q-1; Sun, 24 Oct 2021 22:55:00 -0400 X-MC-Unique: gh3LXyuHM9el8AtAnQEg4Q-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0569D1808302; Mon, 25 Oct 2021 02:54:59 +0000 (UTC) Received: from localhost (ovpn-8-18.pek2.redhat.com [10.72.8.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id D39585D705; Mon, 25 Oct 2021 02:54:55 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Luis Chamberlain , Minchan Kim , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Ming Lei Subject: [PATCH V3 3/4] zram: avoid race between zram_remove and disksize_store Date: Mon, 25 Oct 2021 10:54:25 +0800 Message-Id: <20211025025426.2815424-4-ming.lei@redhat.com> In-Reply-To: <20211025025426.2815424-1-ming.lei@redhat.com> References: <20211025025426.2815424-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org After resetting device in zram_remove(), disksize_store still may come and allocate resources again before deleting gendisk, fix the race by resetting zram after del_gendisk() returns. At that time, disksize_store can't come any more. Reported-by: Luis Chamberlain Reviewed-by: Luis Chamberlain Signed-off-by: Ming Lei --- drivers/block/zram/zram_drv.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 8883de7aa3d7..dba93b8ce511 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2002,6 +2002,13 @@ static int zram_remove(struct zram *zram) /* del_gendisk drains pending reset_store */ WARN_ON_ONCE(claimed && zram->claim); + /* + * disksize_store() may be called in between zram_reset_device() + * and del_gendisk(), so run the last reset to avoid leaking + * anything allocated with disksize_store() + */ + zram_reset_device(zram); + blk_cleanup_disk(zram->disk); kfree(zram); return 0; -- 2.31.1