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 X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6C32C04AB5 for ; Mon, 3 Jun 2019 12:41:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CE772807D for ; Mon, 3 Jun 2019 12:41:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727506AbfFCMlf (ORCPT ); Mon, 3 Jun 2019 08:41:35 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:17660 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726137AbfFCMlf (ORCPT ); Mon, 3 Jun 2019 08:41:35 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 54A4B40C7BBAC10F9B8E; Mon, 3 Jun 2019 20:41:33 +0800 (CST) Received: from [127.0.0.1] (10.133.213.239) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.439.0; Mon, 3 Jun 2019 20:41:32 +0800 Subject: Re: [PATCH v2] kernel/module: Fix mem leak in module_add_modinfo_attrs To: Jessica Yu References: <20190515161212.28040-1-yuehaibing@huawei.com> <20190530134304.4976-1-yuehaibing@huawei.com> <20190603104716.GA21759@linux-8ccs> CC: , , From: Yuehaibing Message-ID: <131515d0-652a-c292-ec17-0722e2a4d465@huawei.com> Date: Mon, 3 Jun 2019 20:41:32 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <20190603104716.GA21759@linux-8ccs> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.133.213.239] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/6/3 18:47, Jessica Yu wrote: > +++ YueHaibing [30/05/19 21:43 +0800]: >> In module_add_modinfo_attrs if sysfs_create_file >> fails, we forget to free allocated modinfo_attrs >> and roll back the sysfs files. >> >> Fixes: 03e88ae1b13d ("[PATCH] fix module sysfs files reference counting") >> Signed-off-by: YueHaibing >> --- >> v2: free from '--i' instead of 'i--' >> --- >> kernel/module.c | 16 +++++++++++++++- >> 1 file changed, 15 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/module.c b/kernel/module.c >> index 6e6712b..78e21a7 100644 >> --- a/kernel/module.c >> +++ b/kernel/module.c >> @@ -1723,15 +1723,29 @@ static int module_add_modinfo_attrs(struct module *mod) >> return -ENOMEM; >> >> temp_attr = mod->modinfo_attrs; >> - for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) { >> + for (i = 0; (attr = modinfo_attrs[i]); i++) { >> if (!attr->test || attr->test(mod)) { >> memcpy(temp_attr, attr, sizeof(*temp_attr)); >> sysfs_attr_init(&temp_attr->attr); >> error = sysfs_create_file(&mod->mkobj.kobj, >> &temp_attr->attr); >> + if (error) >> + goto error_out; >> ++temp_attr; >> } >> } >> + >> + return 0; >> + >> +error_out: >> + for (; (attr = &mod->modinfo_attrs[i]) && i >= 0; --i) { > > The increment step is executed after the body of the loop, so this is > still starting at i instead of i - 1. I think we need: > > for (--i; (attr = &mod->modinfo_attrs[i]) && i >= 0; i--) oops, my bad, will fix it. > > Thanks, > > Jessica > >> + if (!attr->attr.name) >> + break; >> + sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); >> + if (attr->free) >> + attr->free(mod); >> + } >> + kfree(mod->modinfo_attrs); >> return error; >> } >> >> -- >> 2.7.4 >> >> > > . >