From patchwork Tue Jan 19 06:29:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: liu xiang X-Patchwork-Id: 366450 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=ham 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 30251C433DB for ; Tue, 19 Jan 2021 06:31:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E874822CB1 for ; Tue, 19 Jan 2021 06:31:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729354AbhASGao (ORCPT ); Tue, 19 Jan 2021 01:30:44 -0500 Received: from out28-148.mail.aliyun.com ([115.124.28.148]:48368 "EHLO out28-148.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729463AbhASG37 (ORCPT ); Tue, 19 Jan 2021 01:29:59 -0500 X-Alimail-AntiSpam: AC=CONTINUE; BC=0.1089962|-1; CH=green; DM=|CONTINUE|false|; DS=CONTINUE|ham_alarm|0.00400365-0.000545466-0.995451; FP=11637145905088366247|1|1|1|0|-1|-1|-1; HT=ay29a033018047203; MF=liu.xiang@zlingsmart.com; NM=1; PH=DS; RN=9; RT=9; SR=0; TI=SMTPD_---.JMd8d.7_1611037752; Received: from localhost(mailfrom:liu.xiang@zlingsmart.com fp:SMTPD_---.JMd8d.7_1611037752) by smtp.aliyun-inc.com(10.194.97.246); Tue, 19 Jan 2021 14:29:12 +0800 From: Liu Xiang To: linux-gpio@vger.kernel.org Cc: linus.walleij@linaro.org, mripard@kernel.org, wens@csie.org, jernej.skrabec@siol.net, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, liuxiang_1999@126.com, Liu Xiang Subject: [PATCH] pinctrl: sunxi: fix use-after-free in sunxi_pmx_free() Date: Tue, 19 Jan 2021 14:29:08 +0800 Message-Id: <20210119062908.20169-1-liu.xiang@zlingsmart.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org When CONFIG_REGULATOR is not set, sunxi_pmx_request() always return success. Even a group of pins call sunxi_pmx_request(), the refcount is only 1. This can cause a use-after-free warning in sunxi_pmx_free(). To solve this problem, go to err path if regulator_get() return NULL or error. Signed-off-by: Liu Xiang --- drivers/pinctrl/sunxi/pinctrl-sunxi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/pinctrl/sunxi/pinctrl-sunxi.c b/drivers/pinctrl/sunxi/pinctrl-sunxi.c index dc8d39ae0..d1a8974eb 100644 --- a/drivers/pinctrl/sunxi/pinctrl-sunxi.c +++ b/drivers/pinctrl/sunxi/pinctrl-sunxi.c @@ -777,7 +777,7 @@ static int sunxi_pmx_request(struct pinctrl_dev *pctldev, unsigned offset) snprintf(supply, sizeof(supply), "vcc-p%c", 'a' + bank); reg = regulator_get(pctl->dev, supply); - if (IS_ERR(reg)) { + if (IS_ERR_OR_NULL(reg)) { dev_err(pctl->dev, "Couldn't get bank P%c regulator\n", 'A' + bank); return PTR_ERR(reg); @@ -811,7 +811,7 @@ static int sunxi_pmx_free(struct pinctrl_dev *pctldev, unsigned offset) PINS_PER_BANK; struct sunxi_pinctrl_regulator *s_reg = &pctl->regulators[bank_offset]; - if (!refcount_dec_and_test(&s_reg->refcount)) + if (!s_reg->regulator || !refcount_dec_and_test(&s_reg->refcount)) return 0; regulator_disable(s_reg->regulator);