From nobody Tue Jun 23 03:13:13 2026 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 33880C433EF for ; Fri, 11 Mar 2022 09:37:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347428AbiCKJiV (ORCPT ); Fri, 11 Mar 2022 04:38:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232430AbiCKJiT (ORCPT ); Fri, 11 Mar 2022 04:38:19 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79AE01BE0F8 for ; Fri, 11 Mar 2022 01:37:16 -0800 (PST) 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: quoted-printable 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 spinloc= k") 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 =3D kmem_cache_alloc(policy_cache, GFP_KERNEL); if (!mpol_new) goto err_out; + refcount_set(&mpol_new->refcnt, 1); goto restart; } =20 --=20 2.23.0