From patchwork Thu Mar 10 13:24:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12776336 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 54BBFC433EF for ; Thu, 10 Mar 2022 13:25:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A194D8D0002; Thu, 10 Mar 2022 08:25:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C83C8D0001; Thu, 10 Mar 2022 08:25:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 890AA8D0002; Thu, 10 Mar 2022 08:25:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 7B6AA8D0001 for ; Thu, 10 Mar 2022 08:25:12 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 465B023E06 for ; Thu, 10 Mar 2022 13:25:12 +0000 (UTC) X-FDA: 79228547664.03.D2B0D9F Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf17.hostedemail.com (Postfix) with ESMTP id 0C2BB40024 for ; Thu, 10 Mar 2022 13:25:09 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KDqWz6Bjpzdb7R; Thu, 10 Mar 2022 21:23:43 +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; Thu, 10 Mar 2022 21:25:06 +0800 From: Miaohe Lin To: CC: , , , , Subject: [PATCH] mm/mlock: fix potential imbalanced rlimit ucounts adjustment Date: Thu, 10 Mar 2022 21:24:17 +0800 Message-ID: <20220310132417.41189-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: 0C2BB40024 X-Stat-Signature: 3w1n6jkr7yuogwasse7m7op5khpck58a Authentication-Results: imf17.hostedemail.com; dkim=none; spf=pass (imf17.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-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1646918709-603607 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: user_shm_lock forgets to set allowed to 0 when get_ucounts fails. So the later user_shm_unlock might do the extra dec_rlimit_ucounts. Fix this by resetting allowed to 0. Fixes: 5ed44a401ddf ("do not limit locked memory when RLIMIT_MEMLOCK is RLIM_INFINITY") Signed-off-by: Miaohe Lin Acked-by: Hugh Dickins --- mm/mlock.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/mlock.c b/mm/mlock.c index 29372c0eebe5..efd2dd2943de 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -733,6 +733,7 @@ int user_shm_lock(size_t size, struct ucounts *ucounts) } if (!get_ucounts(ucounts)) { dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked); + allowed = 0; goto out; } allowed = 1;