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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 2FBDEC433E0 for ; Fri, 24 Jul 2020 00:50:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 070232068F for ; Fri, 24 Jul 2020 00:50:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728387AbgGXAuT (ORCPT ); Thu, 23 Jul 2020 20:50:19 -0400 Received: from mleia.com ([178.79.152.223]:35378 "EHLO mail.mleia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727783AbgGXAuT (ORCPT ); Thu, 23 Jul 2020 20:50:19 -0400 Received: from mail.mleia.com (localhost [127.0.0.1]) by mail.mleia.com (Postfix) with ESMTP id 527DA3F9092; Fri, 24 Jul 2020 00:50:17 +0000 (UTC) From: Vladimir Zapolskiy To: Liam Girdwood , Mark Brown Cc: Wen Yang , linux-kernel@vger.kernel.org Subject: [PATCH] regulator: fix memory leak on error path of regulator_register() Date: Fri, 24 Jul 2020 03:50:13 +0300 Message-Id: <20200724005013.23278-1-vz@mleia.com> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-49551924 X-CRM114-CacheID: sfid-20200724_005017_358293_61AE4293 X-CRM114-Status: GOOD ( 13.97 ) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The change corrects registration and deregistration on error path of a regulator, the problem was manifested by a reported memory leak on deferred probe: as3722-regulator as3722-regulator: regulator 13 register failed -517 # cat /sys/kernel/debug/kmemleak unreferenced object 0xecc43740 (size 64): comm "swapper/0", pid 1, jiffies 4294937640 (age 712.880s) hex dump (first 32 bytes): 72 65 67 75 6c 61 74 6f 72 2e 32 34 00 5a 5a 5a regulator.24.ZZZ 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ backtrace: [<0c4c3d1c>] __kmalloc_track_caller+0x15c/0x2c0 [<40c0ad48>] kvasprintf+0x64/0xd4 [<109abd29>] kvasprintf_const+0x70/0x84 [] kobject_set_name_vargs+0x34/0xa8 [<62282ea2>] dev_set_name+0x40/0x64 [] regulator_register+0x3a4/0x1344 [<16a9543f>] devm_regulator_register+0x4c/0x84 [<51a4c6a1>] as3722_regulator_probe+0x294/0x754 ... The memory leak problem was introduced as a side ef another fix in regulator_register() error path, I believe that the proper fix is to decouple device_register() function into its two compounds and initialize a struct device before assigning any values to its fields and then using it before actual registration of a device happens. This lets to call put_device() safely after initialization, and, since now a release callback is called, kfree(rdev->constraints) shall be removed to exclude a double free condition. Fixes: a3cde9534ebd ("regulator: core: fix regulator_register() error paths to properly release rdev") Cc: Wen Yang Signed-off-by: Vladimir Zapolskiy --- drivers/regulator/core.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 03154f5b939f..720f28844795 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -5023,7 +5023,6 @@ regulator_register(const struct regulator_desc *regulator_desc, struct regulator_dev *rdev; bool dangling_cfg_gpiod = false; bool dangling_of_gpiod = false; - bool reg_device_fail = false; struct device *dev; int ret, i; @@ -5152,10 +5151,12 @@ regulator_register(const struct regulator_desc *regulator_desc, } /* register with sysfs */ + device_initialize(&rdev->dev); rdev->dev.class = ®ulator_class; rdev->dev.parent = dev; dev_set_name(&rdev->dev, "regulator.%lu", (unsigned long) atomic_inc_return(®ulator_no)); + dev_set_drvdata(&rdev->dev, rdev); /* set regulator constraints */ if (init_data) @@ -5206,12 +5207,9 @@ regulator_register(const struct regulator_desc *regulator_desc, !rdev->desc->fixed_uV) rdev->is_switch = true; - dev_set_drvdata(&rdev->dev, rdev); - ret = device_register(&rdev->dev); - if (ret != 0) { - reg_device_fail = true; + ret = device_add(&rdev->dev); + if (ret != 0) goto unset_supplies; - } rdev_init_debugfs(rdev); @@ -5233,17 +5231,15 @@ regulator_register(const struct regulator_desc *regulator_desc, mutex_unlock(®ulator_list_mutex); wash: kfree(rdev->coupling_desc.coupled_rdevs); - kfree(rdev->constraints); mutex_lock(®ulator_list_mutex); regulator_ena_gpio_free(rdev); mutex_unlock(®ulator_list_mutex); + put_device(&rdev->dev); + rdev = NULL; clean: if (dangling_of_gpiod) gpiod_put(config->ena_gpiod); - if (reg_device_fail) - put_device(&rdev->dev); - else - kfree(rdev); + kfree(rdev); kfree(config); rinse: if (dangling_cfg_gpiod) -- 2.24.0