From nobody Tue Apr 7 17:39:25 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 93AEFC4332F for ; Tue, 18 Oct 2022 14:38:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230413AbiJROiE (ORCPT ); Tue, 18 Oct 2022 10:38:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230341AbiJROiB (ORCPT ); Tue, 18 Oct 2022 10:38:01 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 947F2CA8B6 for ; Tue, 18 Oct 2022 07:37:57 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id x31-20020a17090a38a200b0020d2afec803so14195298pjb.2 for ; Tue, 18 Oct 2022 07:37:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=zwuWy4jARkZiYQhQKKp3kZsxq7qh8bIcksVC/zF6xJY=; b=eM6DqSRMVv1I6J8Rz4Q13ykLhUES0rYe2ZYVOe4gWNOOFdM/+7+opEMdjXhtGxPWjZ bkpiva/nANsSBAd4nBXwf5CJkXPZHwmTP86j6+lVmWxtrTwFUtpjEBWUaQBk7vPcqxG+ /WNRm2BiHWURU4dh5cUAPm1sloxCaP5vAwC2ysF+c3V73d8Kd85G8tfakguKHGjXbCT2 NN/bPmOoeKedMKykOVFqW/7QOoreIvYon+Ktf8REPPEcnQfj4/j3pzg9f+bR/JUxL5Bh Z7OYmQTVl6APm14AWCO7NdZE+i3+PGBOSSNLz3zsolKGxdt1BaXfdKu9hlAsH/C09RpX 3+Og== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=zwuWy4jARkZiYQhQKKp3kZsxq7qh8bIcksVC/zF6xJY=; b=JHRbfdcr2g+i7aMgBD+Hv8mDkgcH1ZOTOigiE/Jp6cYFGtlHKr1I8o9pYRCLRyOe94 z02dBgJOYo2Cb56OwUNKFwQ/OrynBHHYcjImYec7hKXZ+NUlHxngs9sbiYWaaPp3Nabn rEQ5/6fbeD1s+lDd3Kl0rSW+lger7QJN1PWLolBlHi4FAEzvCos7B+nXLHiIkPllPKT1 5ZAqWZbrrC9nHSyKLXgdno0XdOkzWJ8lfV0ofvP85alWHO41P+GCyA645IXy16oywwwJ PemoOBLJjbnlpEra/zitWTdljiIoC4yrbbh5UwcksV9mVMkuGiSI409odqUjqwmxdOVt urDQ== X-Gm-Message-State: ACrzQf3m+0XdAIREcu+m1Eo5yWOK0ogZ3bl68W8+0uw80Ef4nw1rHXfB 19lpWUHDORiU8hiEtZNXLQyITUmcQ6JsNw== X-Google-Smtp-Source: AMsMyM54iVDRJ+YG116kjqtwzeL/Vs0TW/7yChUCfXljnPckCF3wWpxsUUte6Jy+ewQHHv1xjgFtGQ== X-Received: by 2002:a17:90a:c7d3:b0:20a:68a1:85cb with SMTP id gf19-20020a17090ac7d300b0020a68a185cbmr40099316pjb.138.1666103876522; Tue, 18 Oct 2022 07:37:56 -0700 (PDT) Received: from localhost.localdomain ([182.160.5.243]) by smtp.gmail.com with ESMTPSA id b16-20020a170902e95000b0017b264a2d4asm8814839pll.44.2022.10.18.07.37.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Oct 2022 07:37:56 -0700 (PDT) From: Tuo Cao <91tuocao@gmail.com> To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, 91tuocao@gmail.com Subject: [PATCH] mm: folio-compat: fix bug for pagecache_get_page Date: Tue, 18 Oct 2022 22:36:39 +0800 Message-Id: <20221018143639.5099-1-91tuocao@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The folio returned from __filemap_get_folio may be a NULL, it will causes the kernel crash when access folio->page. Signed-off-by: Tuo Cao <91tuocao@gmail.com> --- mm/folio-compat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/folio-compat.c b/mm/folio-compat.c index e1e23b4947d7..37ba33135506 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -108,7 +108,7 @@ 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 ((fgp_flags & FGP_HEAD) || xa_is_value(folio)) return &folio->page; return folio_file_page(folio, index); } --=20 2.17.1