From patchwork Sat Aug 7 09:36:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12424257 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=ham 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 97844C19F34 for ; Sat, 7 Aug 2021 09:36:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F31FC60FE7 for ; Sat, 7 Aug 2021 09:36:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org F31FC60FE7 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 91B1F6B0072; Sat, 7 Aug 2021 05:36:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5B3FD6B0073; Sat, 7 Aug 2021 05:36:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C6EF6B0072; Sat, 7 Aug 2021 05:36:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0124.hostedemail.com [216.40.44.124]) by kanga.kvack.org (Postfix) with ESMTP id E19776B0072 for ; Sat, 7 Aug 2021 05:36:22 -0400 (EDT) Received: from smtpin32.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 8DDF01D5EA for ; Sat, 7 Aug 2021 09:36:22 +0000 (UTC) X-FDA: 78447779004.32.547E9DA Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by imf01.hostedemail.com (Postfix) with ESMTP id C796E5033FB3 for ; Sat, 7 Aug 2021 09:36:21 +0000 (UTC) Received: from dggeme703-chm.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Ghcfd6sNTz1CT3G; Sat, 7 Aug 2021 17:36:09 +0800 (CST) Received: from huawei.com (10.175.124.27) by dggeme703-chm.china.huawei.com (10.1.199.99) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Sat, 7 Aug 2021 17:36:19 +0800 From: Miaohe Lin To: CC: , , , , , , Subject: [PATCH 4/5] mm: gup: fix potential pgmap refcnt leak in __gup_device_huge() Date: Sat, 7 Aug 2021 17:36:19 +0800 Message-ID: <20210807093620.21347-5-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20210807093620.21347-1-linmiaohe@huawei.com> References: <20210807093620.21347-1-linmiaohe@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggeme703-chm.china.huawei.com (10.1.199.99) X-CFilter-Loop: Reflected X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: C796E5033FB3 Authentication-Results: imf01.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=huawei.com; spf=pass (imf01.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.255 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Stat-Signature: af5acn995ib8gaxp9xhpy4ezcfjb63kk X-HE-Tag: 1628328981-984724 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: When failed to try_grab_page, put_dev_pagemap() is missed. So pgmap refcnt will leak in this case. Also we remove the check for pgmap against NULL as it's also checked inside the put_dev_pagemap(). Signed-off-by: Miaohe Lin Fixes: 3faa52c03f44 ("mm/gup: track FOLL_PIN pages") Reviewed-by: John Hubbard --- mm/gup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index d7e4507de6b1..8c89e614d4aa 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2253,14 +2253,14 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr, pages[*nr] = page; if (unlikely(!try_grab_page(page, flags))) { undo_dev_pagemap(nr, nr_start, flags, pages); + put_dev_pagemap(pgmap); return 0; } (*nr)++; pfn++; } while (addr += PAGE_SIZE, addr != end); - if (pgmap) - put_dev_pagemap(pgmap); + put_dev_pagemap(pgmap); return 1; }