From patchwork Mon Sep 27 02:09:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 12518991 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 1C482C433FE for ; Mon, 27 Sep 2021 02:06:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 85EB060EB4 for ; Mon, 27 Sep 2021 02:06:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 85EB060EB4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id ECCD06B0071; Sun, 26 Sep 2021 22:06:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E550B6B0072; Sun, 26 Sep 2021 22:06:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D1CD8900002; Sun, 26 Sep 2021 22:06:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0204.hostedemail.com [216.40.44.204]) by kanga.kvack.org (Postfix) with ESMTP id BEB606B0071 for ; Sun, 26 Sep 2021 22:06:45 -0400 (EDT) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 78FED2CFE0 for ; Mon, 27 Sep 2021 02:06:45 +0000 (UTC) X-FDA: 78631714770.25.BF79731 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf08.hostedemail.com (Postfix) with ESMTP id D694030000A8 for ; Mon, 27 Sep 2021 02:06:44 +0000 (UTC) Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4HHmFV5Ysqz8tHm; Mon, 27 Sep 2021 10:05:50 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Mon, 27 Sep 2021 10:06:40 +0800 Received: from localhost.localdomain.localdomain (10.175.113.25) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Mon, 27 Sep 2021 10:06:39 +0800 From: Kefeng Wang To: , , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , , CC: Kefeng Wang Subject: [PATCH] slub: Add back check for free nonslab objects Date: Mon, 27 Sep 2021 10:09:22 +0800 Message-ID: <20210927020922.87449-1-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-Originating-IP: [10.175.113.25] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: D694030000A8 X-Stat-Signature: hu3noruwgyfrp59dqrnw6wnbxhghnro1 Authentication-Results: imf08.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=huawei.com; spf=pass (imf08.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com X-Rspamd-Server: rspam06 X-HE-Tag: 1632708404-531699 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: After commit ("f227f0faf63b slub: fix unreclaimable slab stat for bulk free"), the check for free nonslab page is replaced by VM_BUG_ON_PAGE, which only check with CONFIG_DEBUG_VM enabled, but this config may impact performance, so it only for debug. Commit ("0937502af7c9 slub: Add check for kfree() of non slab objects.") add the ability, which should be needed in any configs to catch the invalid free, they even could be potential issue, eg, memory corruption, use after free and double free, so replace VM_BUG_ON_PAGE to WARN_ON, and add dump_page() to help use to debug the issue. Signed-off-by: Kefeng Wang --- mm/slub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 3095b889fab4..1bfe09098485 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3522,7 +3522,8 @@ static inline void free_nonslab_page(struct page *page, void *object) { unsigned int order = compound_order(page); - VM_BUG_ON_PAGE(!PageCompound(page), page); + if (WARN_ON(!PageCompound(page))) + dump_page(page); kfree_hook(object); mod_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B, -(PAGE_SIZE << order)); __free_pages(page, order);