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 2B6C0C38A2D for ; Mon, 24 Oct 2022 17:47:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232067AbiJXRrV (ORCPT ); Mon, 24 Oct 2022 13:47:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231881AbiJXRq6 (ORCPT ); Mon, 24 Oct 2022 13:46:58 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BB152D1E2 for ; Mon, 24 Oct 2022 09:22:47 -0700 (PDT) Received: from dggpemm500023.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MwvD90QZGzVhmf; Mon, 24 Oct 2022 20:15:37 +0800 (CST) Received: from dggpemm500007.china.huawei.com (7.185.36.183) by dggpemm500023.china.huawei.com (7.185.36.83) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 24 Oct 2022 20:20:21 +0800 Received: from huawei.com (10.175.103.91) by dggpemm500007.china.huawei.com (7.185.36.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 24 Oct 2022 20:20:20 +0800 From: Yang Yingliang To: , , , , , , CC: , , , , , , , , , , , , , , , Subject: [PATCH v2] kset: fix memory leak when kset_register() returns error Date: Mon, 24 Oct 2022 20:19:10 +0800 Message-ID: <20221024121910.1169801-1-yangyingliang@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.103.91] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500007.china.huawei.com (7.185.36.183) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Inject fault while loading module, kset_register() may fail. If it fails, the name allocated by kobject_set_name() which is called before kset_register() is leaked, because refcount of kobject is hold in kset_init(). As a kset may be embedded in a larger structure which needs be freed in release() function or error path in callers, we can not call kset_put() in kset_register(), or it will cause double free, so just call kfree_const() to free the name and set it to NULL. With this fix, the callers don't need to care about the name freeing and call an extra kset_put() if kset_register() fails. Suggested-by: Luben Tuikov Signed-off-by: Yang Yingliang --- v1 -> v2: Free name inside of kset_register() instead of calling kset_put() in drivers. --- lib/kobject.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/lib/kobject.c b/lib/kobject.c index a0b2dbfcfa23..3409a89c81e5 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -834,6 +834,9 @@ EXPORT_SYMBOL_GPL(kobj_sysfs_ops); /** * kset_register() - Initialize and add a kset. * @k: kset. + * + * NOTE: On error, the kset.kobj.name allocated by() kobj_set_name() + * which is called before kset_register() in caller need be freed. */ int kset_register(struct kset *k) { @@ -844,8 +847,11 @@ int kset_register(struct kset *k) kset_init(k); err = kobject_add_internal(&k->kobj); - if (err) + if (err) { + kfree_const(k->kobj.name); + k->kobj.name = NULL; return err; + } kobject_uevent(&k->kobj, KOBJ_ADD); return 0; } -- 2.25.1