From nobody Wed Apr 15 04:30:53 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 2F10AC04A68 for ; Wed, 27 Jul 2022 06:50:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230296AbiG0GuK (ORCPT ); Wed, 27 Jul 2022 02:50:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230267AbiG0Gth (ORCPT ); Wed, 27 Jul 2022 02:49:37 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E1C6481DC for ; Tue, 26 Jul 2022 23:46:46 -0700 (PDT) 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 Content-Transfer-Encoding: quoted-printable 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 *m= apping, pgoff_t index, struct folio *folio; =20 folio =3D __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); } --=20 2.25.1