From patchwork Fri Nov 12 12:44:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12616777 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92FE1C433F5 for ; Fri, 12 Nov 2021 13:00:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6122561078 for ; Fri, 12 Nov 2021 13:00:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6122561078 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 D384D6B0074; Fri, 12 Nov 2021 08:00:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CE7496B0078; Fri, 12 Nov 2021 08:00:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BFED76B007B; Fri, 12 Nov 2021 08:00:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0087.hostedemail.com [216.40.44.87]) by kanga.kvack.org (Postfix) with ESMTP id AE02E6B0074 for ; Fri, 12 Nov 2021 08:00:32 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 6E7BF18528A83 for ; Fri, 12 Nov 2021 13:00:32 +0000 (UTC) X-FDA: 78800287104.06.ADAD68A Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by imf16.hostedemail.com (Postfix) with ESMTP id D775BF0000B6 for ; Fri, 12 Nov 2021 13:00:18 +0000 (UTC) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4HrJDx5BRjz67ZgZ; Fri, 12 Nov 2021 20:44:17 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Fri, 12 Nov 2021 13:44:42 +0100 From: Roberto Sassu To: , , , , , CC: , , , , , , Roberto Sassu Subject: [RFC][PATCH 4/5] shmem: Avoid segfault in shmem_read_mapping_page_gfp() Date: Fri, 12 Nov 2021 13:44:10 +0100 Message-ID: <20211112124411.1948809-5-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211112124411.1948809-1-roberto.sassu@huawei.com> References: <20211112124411.1948809-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml753-chm.china.huawei.com (10.201.108.203) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Authentication-Results: imf16.hostedemail.com; dkim=none; spf=pass (imf16.hostedemail.com: domain of roberto.sassu@huawei.com designates 185.176.79.56 as permitted sender) smtp.mailfrom=roberto.sassu@huawei.com; dmarc=pass (policy=none) header.from=huawei.com X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: D775BF0000B6 X-Stat-Signature: 5gcxowjxduc33p3o96xkjb814rajrc9h X-HE-Tag: 1636722018-240846 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: Check the hwpoison page flag only if the page is valid in shmem_read_mapping_page_gfp(). The PageHWPoison() macro tries to access the page flags and cannot work on an error pointer. Signed-off-by: Roberto Sassu --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index 23c91a8beb78..427863cbf0dc 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -4222,7 +4222,7 @@ struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, else unlock_page(page); - if (PageHWPoison(page)) + if (!IS_ERR(page) && PageHWPoison(page)) page = ERR_PTR(-EIO); return page;