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 13D6EC433FE for ; Wed, 30 Nov 2022 01:17:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230505AbiK3BRr (ORCPT ); Tue, 29 Nov 2022 20:17:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229648AbiK3BRm (ORCPT ); Tue, 29 Nov 2022 20:17:42 -0500 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E619D6456; Tue, 29 Nov 2022 17:17:37 -0800 (PST) Received: from kwepemi500008.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4NMLs40M6vz15MxS; Wed, 30 Nov 2022 09:16:56 +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 15.1.2375.31; Wed, 30 Nov 2022 09:17:35 +0800 Message-ID: <600ceae6-e476-aa2a-15de-cace3afee2fa@huawei.com> Date: Wed, 30 Nov 2022 09:17:34 +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] vfio/mdev: fix possible memory leak in module init funcs To: , , , , , References: <20221118032827.3725190-1-ruanjinjie@huawei.com> Content-Language: en-US From: Ruan Jinjie In-Reply-To: <20221118032827.3725190-1-ruanjinjie@huawei.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500008.china.huawei.com (7.221.188.139) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ping. On 2022/11/18 11:28, ruanjinjie wrote: > Inject fault while probing module, if device_register() fails, > but the refcount of kobject is not decreased to 0, the name > allocated in dev_set_name() is leaked. Fix this by calling > put_device(), so that name can be freed in callback function > kobject_cleanup(). > > unreferenced object 0xffff88807d687008 (size 8): > comm "modprobe", pid 8280, jiffies 4294807686 (age 12.378s) > hex dump (first 8 bytes): > 6d 64 70 79 00 6b 6b a5 mdpy.kk. > backtrace: > [] __kmalloc_node_track_caller+0x4e/0x150 > [] kstrdup+0x33/0x60 > [] kobject_set_name_vargs+0x41/0x110 > [] dev_set_name+0xab/0xe0 > [] 0xffffffffa0260105 > [] do_one_initcall+0x87/0x2e0 > [] do_init_module+0x1ab/0x640 > [] load_module+0x5d00/0x77f0 > [] __do_sys_finit_module+0x110/0x1b0 > [] do_syscall_64+0x35/0x80 > [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > unreferenced object 0xffff888101ccbcf8 (size 8): > comm "modprobe", pid 15662, jiffies 4295164481 (age 13.282s) > hex dump (first 8 bytes): > 6d 74 74 79 00 6b 6b a5 mtty.kk. > backtrace: > [] __kmalloc_node_track_caller+0x4e/0x150 > [] kstrdup+0x33/0x60 > [] kobject_set_name_vargs+0x41/0x110 > [] dev_set_name+0xab/0xe0 > [] 0xffffffffa0248134 > [] do_one_initcall+0x87/0x2e0 > [] do_init_module+0x1ab/0x640 > [] load_module+0x5d00/0x77f0 > [] __do_sys_finit_module+0x110/0x1b0 > [] do_syscall_64+0x35/0x80 > [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > unreferenced object 0xffff88810177c6c8 (size 8): > comm "modprobe", pid 23657, jiffies 4295314656 (age 13.227s) > hex dump (first 8 bytes): > 6d 62 6f 63 68 73 00 a5 mbochs.. > backtrace: > [] __kmalloc_node_track_caller+0x4e/0x150 > [] kstrdup+0x33/0x60 > [] kobject_set_name_vargs+0x41/0x110 > [] dev_set_name+0xab/0xe0 > [] 0xffffffffa0248124 > [] do_one_initcall+0x87/0x2e0 > [] do_init_module+0x1ab/0x640 > [] load_module+0x5d00/0x77f0 > [] __do_sys_finit_module+0x110/0x1b0 > [] do_syscall_64+0x35/0x80 > [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 > > Fixes: d61fc96f47fd ("sample: vfio mdev display - host device") > Fixes: 9d1a546c53b4 ("docs: Sample driver to demonstrate how to use Mediated device framework.") > Fixes: a5e6e6505f38 ("sample: vfio bochs vbe display (host device for bochs-drm)") > Signed-off-by: ruanjinjie > --- > samples/vfio-mdev/mbochs.c | 4 +++- > samples/vfio-mdev/mdpy.c | 4 +++- > samples/vfio-mdev/mtty.c | 4 +++- > 3 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c > index 117a8d799f71..1c47672be815 100644 > --- a/samples/vfio-mdev/mbochs.c > +++ b/samples/vfio-mdev/mbochs.c > @@ -1430,8 +1430,10 @@ static int __init mbochs_dev_init(void) > dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME); > > ret = device_register(&mbochs_dev); > - if (ret) > + if (ret) { > + put_device(&mbochs_dev); > goto err_class; > + } > > ret = mdev_register_parent(&mbochs_parent, &mbochs_dev, &mbochs_driver, > mbochs_mdev_types, > diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c > index 946e8cfde6fd..bfb93eaf535b 100644 > --- a/samples/vfio-mdev/mdpy.c > +++ b/samples/vfio-mdev/mdpy.c > @@ -717,8 +717,10 @@ static int __init mdpy_dev_init(void) > dev_set_name(&mdpy_dev, "%s", MDPY_NAME); > > ret = device_register(&mdpy_dev); > - if (ret) > + if (ret) { > + put_device(&mdpy_dev); > goto err_class; > + } > > ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver, > mdpy_mdev_types, > diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c > index e72085fc1376..dddb0619846c 100644 > --- a/samples/vfio-mdev/mtty.c > +++ b/samples/vfio-mdev/mtty.c > @@ -1330,8 +1330,10 @@ static int __init mtty_dev_init(void) > dev_set_name(&mtty_dev.dev, "%s", MTTY_NAME); > > ret = device_register(&mtty_dev.dev); > - if (ret) > + if (ret) { > + put_device(&mtty_dev.dev); > goto err_class; > + } > > ret = mdev_register_parent(&mtty_dev.parent, &mtty_dev.dev, > &mtty_driver, mtty_mdev_types,