From patchwork Wed Nov 23 08:16:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Zetao X-Patchwork-Id: 1708162 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4NHCS60HfSz23nw for ; Wed, 23 Nov 2022 18:29:26 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235505AbiKWH3X (ORCPT ); Wed, 23 Nov 2022 02:29:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235343AbiKWH3W (ORCPT ); Wed, 23 Nov 2022 02:29:22 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30476532E3; Tue, 22 Nov 2022 23:29:19 -0800 (PST) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NHCMQ0XB8zqSVt; Wed, 23 Nov 2022 15:25:22 +0800 (CST) Received: from huawei.com (10.67.175.21) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 23 Nov 2022 15:29:16 +0800 From: Li Zetao To: , , CC: , , Subject: [PATCH] i2c: core: Fix possible memleak in i2c_register_adapter() Date: Wed, 23 Nov 2022 16:16:43 +0800 Message-ID: <20221123081643.713184-1-lizetao1@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Originating-IP: [10.67.175.21] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org I got memory leak as follows when doing fault injection test: unreferenced object 0xffff88818be6dcb8 (size 8): comm "modprobe", pid 1022129, jiffies 4363911608 (age 43.838s) hex dump (first 8 bytes): 69 32 63 2d 30 00 6b a5 i2c-0.k. backtrace: [] __kmem_cache_alloc_node+0x2cf/0x4b0 [] __kmalloc_node_track_caller+0x53/0x140 [] kvasprintf+0x6a/0xd0 [] kvasprintf_const+0x77/0xa0 [] kobject_set_name_vargs+0x23/0x90 [] dev_set_name+0x53/0x70 [] i2c_register_adapter+0x112/0x6c0 [i2c_core] [] i2c_add_adapter+0x78/0xc0 [i2c_core] [] piix4_add_adapter+0x132/0x210 [i2c_piix4] [] piix4_probe+0x2d5/0x5f4 [i2c_piix4] [] pci_device_probe+0xb2/0x180 [] really_probe+0xff/0x380 [] __driver_probe_device+0x8a/0x190 [] driver_probe_device+0x23/0xb0 [] __driver_attach+0xd3/0x1b0 [] bus_for_each_dev+0x7e/0xd0 The root cause was traced to an error handing path in i2c_register_adapter() when device_register() fails. After calling dev_set_name() which called by i2c_register_adapter(), the put_device() should be used to give up the device reference in error handling path in order to free "kobj->name" alloced in dev_set_name(). Fix it by calling put_device() when device_register() fails in i2c_register_adapter(). In addition, when i2c_adapter device is released, i2c_adapter_dev_release() is called, in which "dev_released" must be initialized, otherwise a kernel bug will be triggered. Fixes: b119c6c952a0 ("i2c: __must_check fixes (core drivers)") Signed-off-by: Li Zetao --- drivers/i2c/i2c-core-base.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 5dcea9f1deab..ef85e58533e2 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1472,6 +1472,9 @@ static int i2c_register_adapter(struct i2c_adapter *adap) res = device_register(&adap->dev); if (res) { pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); + init_completion(&adap->dev_released); + put_device(&adap->dev); + wait_for_completion(&adap->dev_released); goto out_list; }