From nobody Thu Sep 18 14:08:51 2025 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 D65B6C4708C for ; Tue, 6 Dec 2022 02:59:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233074AbiLFC71 (ORCPT ); Mon, 5 Dec 2022 21:59:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231434AbiLFC7Z (ORCPT ); Mon, 5 Dec 2022 21:59:25 -0500 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78C7E2250A; Mon, 5 Dec 2022 18:59:24 -0800 (PST) Received: by mail-pl1-x62d.google.com with SMTP id p24so12672188plw.1; Mon, 05 Dec 2022 18:59:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=U/4Cj9/05hjAE/KmGhJWxXDEiM3adoyVLnClbzSb1Z8=; b=FFFvWECPjGLnVyC1xHSAxk+j+228qCLvo8kybrm5bnCmzaC67KvmBX0un9mY0+kGHP xq116qzlCeV/O026EgTv4iDlnoUcEfCayjBXrmT7V48huVurbKHdvZUTiZcmy/LZpYH9 VBrda2aaCFamlDih0z9Wq1kpGPmULrtIA2exdhMym21QO80bmAtnqomGjwvjRZHbcgDI NlpUfKhoxfe7LWsKwMVWollmCnpjFWcIu0LnRGeFMDLupgJpUwqsUNvoBHqa1ry9mxwh q8JyczeE4xuzM4z8VZQIVWICa3GeA10Y8AweKdti5nmPynrgMiMz6t0VykOGPztCz6CK 8/AQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=U/4Cj9/05hjAE/KmGhJWxXDEiM3adoyVLnClbzSb1Z8=; b=Eni9OWZQ1RkeyJkoHKyumZpy5PTy3gfoYzzwxv3VQcnVk5a8ivnarZrreiX8Nt/Tc2 g4N03VLBpgM2zIl3DFTgEmJXKdBP1LcOTwW3gR4sTjEvFhI1JSNZOg50g5BSZD6h69/b 8p8ZI/PXVTJ/28g7+zvGyGnMhSozZ0Qj3cGjfv1sU3NR3kiA64VfzKVr5P3ApwcgJFhu QH/KL7JoJzs6sy/t0lEU48RdYhEb0Ju3MZjqCJLrf0/8Y4d1aE2h4AM/ylzX7Llybinh /lVs2I4hM1f/miDcaQtn+oCDcMQkSPlKH3d7lkFPgveZaNRU8TP4O1HCQfo26dV6CZDB Tstg== X-Gm-Message-State: ANoB5pler/rw+/5FH5FadYNCgpRkAMjI26NiJaC7u0tLU4uoAx4HtBVn 9XrF2T+CRsoULpaFJTavn2Q= X-Google-Smtp-Source: AA0mqf5txxt8YXiv04XTW3H78mBdu/lkOdTzM4RB5w74XmUrgNdIVa3BIXgHhmtNBuBjwusRpIaANg== X-Received: by 2002:a17:90a:5918:b0:213:df25:7e8a with SMTP id k24-20020a17090a591800b00213df257e8amr100059081pji.154.1670295563642; Mon, 05 Dec 2022 18:59:23 -0800 (PST) Received: from localhost.localdomain ([2402:7500:587:6b8b:a5d3:fc1e:41e4:9160]) by smtp.gmail.com with ESMTPSA id c6-20020a170902d48600b0017f72a430adsm11315090plg.71.2022.12.05.18.59.17 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 05 Dec 2022 18:59:21 -0800 (PST) From: cy_huang To: broonie@kernel.org Cc: djrscally@gmail.com, hdegoede@redhat.com, markgross@kernel.org, lgirdwood@gmail.com, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, gene_chen@richtek.com, chiaen_wu@richtek.com, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, ChiYuan Huang Subject: [PATCH] regulator: core: Use different devices for resource allocation and DT lookup Date: Tue, 6 Dec 2022 10:59:08 +0800 Message-Id: <1670295548-19598-1-git-send-email-u0084500@gmail.com> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: ChiYuan Huang Following by the below discussion, there's the potential UAF issue between regulator and mfd. https://lore.kernel.org/all/20221128143601.1698148-1-yangyingliang@huawei.c= om/ From the analysis of Yingliang CPU A |CPU B mt6370_probe() | devm_mfd_add_devices() | |mt6370_regulator_probe() | regulator_register() | //allocate init_data and add it to devres | regulator_of_get_init_data() i2c_unregister_device() | device_del() | devres_release_all() | // init_data is freed | release_nodes() | | // using init_data causes UAF | regulator_register() It's common to use mfd core to create child device for the regulator. In order to do the DT lookup for init data, the child that registered the regulator would pass its parent as the parameter. And this causes init data resource allocated to its parent, not itself. The issue happen when parent device is going to release and regulator core is still doing some operation of init data constraint for the regulator of child device. To fix it, this patch expand 'regulator_register' API to use the different devices for init data allocation and DT lookup. Reported-by: Yang Yingliang Signed-off-by: ChiYuan Huang --- Hi, Mark: I have already tested on MT6370. It works. Due to 'regulator_register' API change, There're still two existing users u= se it. I also modify it by the way. --- drivers/platform/x86/intel/int3472/clk_and_regulator.c | 3 ++- drivers/regulator/core.c | 8 ++++---- drivers/regulator/devres.c | 2 +- drivers/regulator/of_regulator.c | 2 +- drivers/regulator/stm32-vrefbuf.c | 2 +- include/linux/regulator/driver.h | 3 ++- 6 files changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/platform/x86/intel/int3472/clk_and_regulator.c b/drive= rs/platform/x86/intel/int3472/clk_and_regulator.c index 1cf9589..c5e3e54d 100644 --- a/drivers/platform/x86/intel/int3472/clk_and_regulator.c +++ b/drivers/platform/x86/intel/int3472/clk_and_regulator.c @@ -185,7 +185,8 @@ int skl_int3472_register_regulator(struct int3472_discr= ete_device *int3472, cfg.init_data =3D &init_data; cfg.ena_gpiod =3D int3472->regulator.gpio; =20 - int3472->regulator.rdev =3D regulator_register(&int3472->regulator.rdesc, + int3472->regulator.rdev =3D regulator_register(int3742->dev, + &int3472->regulator.rdesc, &cfg); if (IS_ERR(int3472->regulator.rdev)) { ret =3D PTR_ERR(int3472->regulator.rdev); diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index e8c00a8..ea4a720 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -5396,6 +5396,7 @@ static struct regulator_coupler generic_regulator_cou= pler =3D { =20 /** * regulator_register - register regulator + * @dev: the device that drive the regulator * @regulator_desc: regulator to register * @cfg: runtime configuration for regulator * @@ -5404,7 +5405,8 @@ static struct regulator_coupler generic_regulator_cou= pler =3D { * or an ERR_PTR() on error. */ struct regulator_dev * -regulator_register(const struct regulator_desc *regulator_desc, +regulator_register(struct device *dev, + const struct regulator_desc *regulator_desc, const struct regulator_config *cfg) { const struct regulator_init_data *init_data; @@ -5413,7 +5415,6 @@ regulator_register(const struct regulator_desc *regul= ator_desc, struct regulator_dev *rdev; bool dangling_cfg_gpiod =3D false; bool dangling_of_gpiod =3D false; - struct device *dev; int ret, i; bool resolved_early =3D false; =20 @@ -5426,8 +5427,7 @@ regulator_register(const struct regulator_desc *regul= ator_desc, goto rinse; } =20 - dev =3D cfg->dev; - WARN_ON(!dev); + WARN_ON(!dev || !cfg->dev); =20 if (regulator_desc->name =3D=3D NULL || regulator_desc->ops =3D=3D NULL) { ret =3D -EINVAL; diff --git a/drivers/regulator/devres.c b/drivers/regulator/devres.c index 3265e75..5c7ff9b 100644 --- a/drivers/regulator/devres.c +++ b/drivers/regulator/devres.c @@ -385,7 +385,7 @@ struct regulator_dev *devm_regulator_register(struct de= vice *dev, if (!ptr) return ERR_PTR(-ENOMEM); =20 - rdev =3D regulator_register(regulator_desc, config); + rdev =3D regulator_register(dev, regulator_desc, config); if (!IS_ERR(rdev)) { *ptr =3D rdev; devres_add(dev, ptr); diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regula= tor.c index 0aff1c2..cd726d4 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -505,7 +505,7 @@ struct regulator_init_data *regulator_of_get_init_data(= struct device *dev, struct device_node *child; struct regulator_init_data *init_data =3D NULL; =20 - child =3D regulator_of_get_init_node(dev, desc); + child =3D regulator_of_get_init_node(config->dev, desc); if (!child) return NULL; =20 diff --git a/drivers/regulator/stm32-vrefbuf.c b/drivers/regulator/stm32-vr= efbuf.c index 30ea3bc..7a454b7 100644 --- a/drivers/regulator/stm32-vrefbuf.c +++ b/drivers/regulator/stm32-vrefbuf.c @@ -210,7 +210,7 @@ static int stm32_vrefbuf_probe(struct platform_device *= pdev) pdev->dev.of_node, &stm32_vrefbuf_regu); =20 - rdev =3D regulator_register(&stm32_vrefbuf_regu, &config); + rdev =3D regulator_register(&pdev->dev, &stm32_vrefbuf_regu, &config); if (IS_ERR(rdev)) { ret =3D PTR_ERR(rdev); dev_err(&pdev->dev, "register failed with error %d\n", ret); diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/dri= ver.h index f9a7461..d3b4a3d 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -687,7 +687,8 @@ static inline int regulator_err2notif(int err) =20 =20 struct regulator_dev * -regulator_register(const struct regulator_desc *regulator_desc, +regulator_register(struct device *dev, + const struct regulator_desc *regulator_desc, const struct regulator_config *config); struct regulator_dev * devm_regulator_register(struct device *dev, --=20 2.7.4