From patchwork Wed Jul 27 06:46:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yongqiang Liu X-Patchwork-Id: 12930162 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 42C35C04A68 for ; Wed, 27 Jul 2022 06:46:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DEEC68E0001; Wed, 27 Jul 2022 02:46:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DC4A76B0081; Wed, 27 Jul 2022 02:46:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CB4728E0001; Wed, 27 Jul 2022 02:46:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id BD4306B0080 for ; Wed, 27 Jul 2022 02:46:49 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id A11F5C0A73 for ; Wed, 27 Jul 2022 06:46:49 +0000 (UTC) X-FDA: 79731946938.16.5C7E131 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf19.hostedemail.com (Postfix) with ESMTP id D2B221A00A3 for ; Wed, 27 Jul 2022 06:46:47 +0000 (UTC) Received: from dggpeml500023.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Lt46H2WnTz9sy9; Wed, 27 Jul 2022 14:45:27 +0800 (CST) Received: from dggpeml500005.china.huawei.com (7.185.36.59) by dggpeml500023.china.huawei.com (7.185.36.114) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 27 Jul 2022 14:46:36 +0800 Received: from huawei.com (10.175.112.125) by dggpeml500005.china.huawei.com (7.185.36.59) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 27 Jul 2022 14:46:35 +0800 From: Yongqiang Liu To: , , , , CC: , , , , Subject: [PATCH] mm/folio-compact: fix potential NULL pointer in pagecache_get_page Date: Wed, 27 Jul 2022 06:46:21 +0000 Message-ID: <20220727064621.534528-1-liuyongqiang13@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500005.china.huawei.com (7.185.36.59) X-CFilter-Loop: Reflected ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658904408; a=rsa-sha256; cv=none; b=1m1QxOGe8VZGhfTojN9ngZLX59H3TIi/WPDu91pAAZeuXxEp4nqlf5wLuKAeTbeW/pZ0OM 6kW+lnNr3qhuWxNOQn6TMugJG1tjup9iR3QyVT18loKmFGZqUgqVbdhI6Qj2Tm6mzIoBXG OPIAtY9NvTTmrQI7bco6W4x9dtO7Eb0= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf19.hostedemail.com: domain of liuyongqiang13@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=liuyongqiang13@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658904408; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references; bh=1JRkM7hVLuJjepy5BDiOI3vBckYoSnCPJWMN3++o2Ps=; b=itAO+Q58zDX//h+eNyKLBQnuzPNDBrCG2CiMo3O4g2bu59s+9DynA1+YcthTmAc0kAURr6 Rr3lyX0XPbRY0RcPkqHlvhhpmYQKJzzif1hn4ImnvrgvtmZY5abfeejdTdgXncxgaUW5lm A2ChMEb7s2Jx2N7k09pasU7aIpRgIaY= X-Rspamd-Queue-Id: D2B221A00A3 X-Rspam-User: X-Stat-Signature: xkjy9gc3oi4pkerumg17mkkjyjs5wpnq Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf19.hostedemail.com: domain of liuyongqiang13@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=liuyongqiang13@huawei.com X-Rspamd-Server: rspam08 X-HE-Tag: 1658904407-38011 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 __filemap_get_folio() failed and returned NULL, we would get a NULL pointer dereference in pagecache_get_page. Fixes: 3f0c6a07fee6 ("mm/filemap: Add filemap_get_folio") Signed-off-by: Yongqiang Liu Cc: # 5.16 --- mm/folio-compat.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 20bc15b57d93..7b21393480e0 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -124,7 +124,9 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, struct folio *folio; folio = __filemap_get_folio(mapping, index, fgp_flags, gfp); - if ((fgp_flags & FGP_HEAD) || !folio || xa_is_value(folio)) + if (!folio) + return NULL; + if ((fgp_flags & FGP_HEAD) || xa_is_value(folio)) return &folio->page; return folio_file_page(folio, index); }