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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5CE98C433FE for ; Fri, 11 Mar 2022 09:37:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ED7D18D0003; Fri, 11 Mar 2022 04:37:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E86118D0001; Fri, 11 Mar 2022 04:37:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D9CF28D0003; Fri, 11 Mar 2022 04:37:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id CBE258D0001 for ; Fri, 11 Mar 2022 04:37:19 -0500 (EST) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id A17FA20BE5 for ; Fri, 11 Mar 2022 09:37:19 +0000 (UTC) X-FDA: 79231602198.05.8CA68CB Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf02.hostedemail.com (Postfix) with ESMTP id ADF1C80023 for ; Fri, 11 Mar 2022 09:37:18 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KFLLb05kqzbbfy; Fri, 11 Mar 2022 17:32:23 +0800 (CST) Received: from huawei.com (10.175.124.27) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 11 Mar 2022 17:37:14 +0800 From: Miaohe Lin To: CC: , , , , Subject: [PATCH] mm/mempolicy: fix potential mpol_new leak in shared_policy_replace Date: Fri, 11 Mar 2022 17:36:24 +0800 Message-ID: <20220311093624.39546-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: ADF1C80023 X-Stat-Signature: bkwpqn9gwkigyiheurq7uuq87tqcuzjb Authentication-Results: imf02.hostedemail.com; dkim=none; spf=pass (imf02.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-HE-Tag: 1646991438-498407 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: If mpol_new is allocated but not used in restart loop, mpol_new will be freed via mpol_put before returning to the caller. But refcnt is not initialized yet, so mpol_put could not do the right things and might leak the unused mpol_new. Fixes: 42288fe366c4 ("mm: mempolicy: Convert shared_policy mutex to spinlock") Signed-off-by: Miaohe Lin --- mm/mempolicy.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 34d2b29c96ad..f19f19d3558b 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2733,6 +2733,7 @@ static int shared_policy_replace(struct shared_policy *sp, unsigned long start, mpol_new = kmem_cache_alloc(policy_cache, GFP_KERNEL); if (!mpol_new) goto err_out; + refcount_set(&mpol_new->refcnt, 1); goto restart; } -- 2.23.0