From patchwork Mon Aug 16 07:21:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Huang X-Patchwork-Id: 12437887 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 B8374C4320E for ; Mon, 16 Aug 2021 07:13:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6D7406023E for ; Mon, 16 Aug 2021 07:13:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6D7406023E 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 F1F2F8D000C; Mon, 16 Aug 2021 03:12:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ECEB78D000B; Mon, 16 Aug 2021 03:12:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D97DF8D000C; Mon, 16 Aug 2021 03:12:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0026.hostedemail.com [216.40.44.26]) by kanga.kvack.org (Postfix) with ESMTP id BE8E08D000B for ; Mon, 16 Aug 2021 03:12:58 -0400 (EDT) Received: from smtpin33.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 72D048249980 for ; Mon, 16 Aug 2021 07:12:58 +0000 (UTC) X-FDA: 78480076836.33.C39BC82 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf10.hostedemail.com (Postfix) with ESMTP id 5CE69600EDE4 for ; Mon, 16 Aug 2021 07:12:57 +0000 (UTC) Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4Gp52m5XqkzYq71; Mon, 16 Aug 2021 15:12:32 +0800 (CST) Received: from dggema756-chm.china.huawei.com (10.1.198.198) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Mon, 16 Aug 2021 15:12:51 +0800 Received: from localhost.localdomain (10.175.112.125) by dggema756-chm.china.huawei.com (10.1.198.198) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Mon, 16 Aug 2021 15:12:51 +0800 From: Chen Huang To: Roman Gushchin , Muchun Song , "Wang Hai" , Greg Kroah-Hartman CC: , , , Chen Huang , "Christoph Lameter" , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , Johannes Weiner , Alexei Starovoitov , Andrew Morton , Linus Torvalds Subject: [PATCH 5.10.y 11/11] mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook() Date: Mon, 16 Aug 2021 07:21:47 +0000 Message-ID: <20210816072147.3481782-12-chenhuang5@huawei.com> X-Mailer: git-send-email 2.18.0.huawei.25 In-Reply-To: <20210816072147.3481782-1-chenhuang5@huawei.com> References: <20210816072147.3481782-1-chenhuang5@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggema756-chm.china.huawei.com (10.1.198.198) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: 5CE69600EDE4 Authentication-Results: imf10.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=huawei.com; spf=pass (imf10.hostedemail.com: domain of chenhuang5@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=chenhuang5@huawei.com X-Rspamd-Server: rspam04 X-Stat-Signature: a3jbob44qjxertszzg3ea81qa557o1a4 X-HE-Tag: 1629097977-369551 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: From: Wang Hai When I use kfree_rcu() to free a large memory allocated by kmalloc_node(), the following dump occurs. BUG: kernel NULL pointer dereference, address: 0000000000000020 [...] Oops: 0000 [#1] SMP [...] Workqueue: events kfree_rcu_work RIP: 0010:__obj_to_index include/linux/slub_def.h:182 [inline] RIP: 0010:obj_to_index include/linux/slub_def.h:191 [inline] RIP: 0010:memcg_slab_free_hook+0x120/0x260 mm/slab.h:363 [...] Call Trace: kmem_cache_free_bulk+0x58/0x630 mm/slub.c:3293 kfree_bulk include/linux/slab.h:413 [inline] kfree_rcu_work+0x1ab/0x200 kernel/rcu/tree.c:3300 process_one_work+0x207/0x530 kernel/workqueue.c:2276 worker_thread+0x320/0x610 kernel/workqueue.c:2422 kthread+0x13d/0x160 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 When kmalloc_node() a large memory, page is allocated, not slab, so when freeing memory via kfree_rcu(), this large memory should not be used by memcg_slab_free_hook(), because memcg_slab_free_hook() is is used for slab. Using page_objcgs_check() instead of page_objcgs() in memcg_slab_free_hook() to fix this bug. Link: https://lkml.kernel.org/r/20210728145655.274476-1-wanghai38@huawei.com Fixes: 270c6a71460e ("mm: memcontrol/slab: Use helpers to access slab page's memcg_data") Signed-off-by: Wang Hai Reviewed-by: Shakeel Butt Acked-by: Michal Hocko Acked-by: Roman Gushchin Reviewed-by: Kefeng Wang Reviewed-by: Muchun Song Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Vlastimil Babka Cc: Johannes Weiner Cc: Alexei Starovoitov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Chen Huang --- mm/slab.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/slab.h b/mm/slab.h index 571757eb4a8f..9759992c720c 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -349,7 +349,7 @@ static inline void memcg_slab_free_hook(struct kmem_cache *s_orig, continue; page = virt_to_head_page(p[i]); - objcgs = page_objcgs(page); + objcgs = page_objcgs_check(page); if (!objcgs) continue;