From mboxrd@z Thu Jan 1 00:00:00 1970 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 CD581C4332F for ; Sun, 11 Dec 2022 02:14:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229775AbiLKCOw (ORCPT ); Sat, 10 Dec 2022 21:14:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229475AbiLKCOv (ORCPT ); Sat, 10 Dec 2022 21:14:51 -0500 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9B8F912AB7; Sat, 10 Dec 2022 18:14:50 -0800 (PST) Received: from kwepemi500008.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4NV7Xf0wWqzJnsN; Sun, 11 Dec 2022 10:11:14 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by kwepemi500008.china.huawei.com (7.221.188.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Sun, 11 Dec 2022 10:14:48 +0800 Message-ID: Date: Sun, 11 Dec 2022 10:14:47 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH] of: overlay: fix null pointer dereferencing in find_dup_cset_node_entry() and find_dup_cset_prop() To: Rob Herring CC: , , References: <20221206083657.3202856-1-ruanjinjie@huawei.com> <20221209205900.GA3808024-robh@kernel.org> Content-Language: en-US From: Ruan Jinjie In-Reply-To: <20221209205900.GA3808024-robh@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemi500008.china.huawei.com (7.221.188.139) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 2022/12/10 4:59, Rob Herring wrote: > On Tue, Dec 06, 2022 at 04:36:57PM +0800, ruanjinjie wrote: >> when kmalloc() fail to allocate memory in kasprintf(), fn_1 or fn_2 will >> be NULL, strcmp() will cause null pointer dereference. >> >> Fixes: 2fe0e8769df9 ("of: overlay: check prevents multiple fragments touching same property") >> Signed-off-by: ruanjinjie >> --- >> drivers/of/overlay.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c >> index bd8ff4df723d..49c066b51148 100644 >> --- a/drivers/of/overlay.c >> +++ b/drivers/of/overlay.c >> @@ -545,6 +545,11 @@ static int find_dup_cset_node_entry(struct overlay_changeset *ovcs, >> >> fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np); >> fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np); >> + if (!fn_1 || !fn_2) { >> + kfree(fn_1); >> + kfree(fn_2); >> + return -ENOMEM; >> + } >> node_path_match = !strcmp(fn_1, fn_2); > > We don't actually care what the return code is, so just change this to: > > node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2); Thank you very much!I'll give the v2 patch soon. > >> kfree(fn_1); >> kfree(fn_2); >> @@ -580,6 +585,11 @@ static int find_dup_cset_prop(struct overlay_changeset *ovcs, >> >> fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np); >> fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np); >> + if (!fn_1 || !fn_2) { >> + kfree(fn_1); >> + kfree(fn_2); >> + return -ENOMEM; >> + } >> node_path_match = !strcmp(fn_1, fn_2); >> kfree(fn_1); >> kfree(fn_2); >> -- >> 2.25.1 >> >> >