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 8A355EB64DB for ; Wed, 14 Jun 2023 06:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241661AbjFNGTV (ORCPT ); Wed, 14 Jun 2023 02:19:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38134 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242982AbjFNGTJ (ORCPT ); Wed, 14 Jun 2023 02:19:09 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFA191BE3; Tue, 13 Jun 2023 23:19:07 -0700 (PDT) Received: from dggpemm500014.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Qgw9W1MSgzqTcl; Wed, 14 Jun 2023 14:14:07 +0800 (CST) Received: from localhost.localdomain (10.175.112.125) by dggpemm500014.china.huawei.com (7.185.36.153) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Wed, 14 Jun 2023 14:19:04 +0800 From: Wupeng Ma To: , CC: , , , Subject: [PATCH stable 5.10 0/1] Fix memleak during hotremove memory Date: Wed, 14 Jun 2023 14:18:59 +0800 Message-ID: <20230614061900.3296725-1-mawupeng1@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500014.china.huawei.com (7.185.36.153) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ma Wupeng Hi maintainers: Our test find a memleak in init_memory_block, it is clear that mem is never been released due to wrong refcount. Commit 08b3acd7a68f ("mm/memory_hotplug: Introduce offline_and_remove_memory()") failed to dec refcount after find_memory_block which fail to dec refcount to zero in remove memory causing the leak. Commit 8dc4bb58a146 ("mm/memory_hotplug: extend offline_and_remove_memory() to handle more than one memory block") introduce walk_memory_blocks to replace find_memory_block which dec refcount by calling put_device after find_memory_block_by_id. In the way, the memleak is fixed. Here is the simplified calltrace: kmem_cache_alloc_trace+0x664/0xed0 init_memory_block+0x8c/0x170 create_memory_block_devices+0xa4/0x150 add_memory_resource+0x188/0x530 __add_memory+0x78/0x104 add_memory+0x6c/0xb0 David Hildenbrand (1): mm/memory_hotplug: extend offline_and_remove_memory() to handle more than one memory block mm/memory_hotplug.c | 105 +++++++++++++++++++++++++++++++++++++------- 1 file changed, 89 insertions(+), 16 deletions(-) -- 2.25.1