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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0989BC433EF for ; Mon, 15 Nov 2021 18:52:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E433E6362E for ; Mon, 15 Nov 2021 18:52:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236995AbhKOSzD (ORCPT ); Mon, 15 Nov 2021 13:55:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:55938 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243001AbhKOSwe (ORCPT ); Mon, 15 Nov 2021 13:52:34 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7E6A163476; Mon, 15 Nov 2021 18:10:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636999814; bh=0qWVlmnLrMZ+EWmiMSXxICve5sLZ/91HU590eReGbM8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IhYyyvXUNqkru0xHGP9gweLteQ5mkjavcUzl0JjjpQpMVb+qGRtl9Fy1+mYu2hiP7 f1ACk6aSEC3Ud1AlNfmjSWNPtpRz3Htc4blqi51oBA2LsTuf2iHp4V0bgQhWKLd+wT eW3j+uGUknD9t1hV2DIaXpbhFjJCS7QJ5jGAW7iA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ziyang Xuan , kernel test robot , Daniel Lezcano , Sasha Levin Subject: [PATCH 5.14 434/849] thermal/core: fix a UAF bug in __thermal_cooling_device_register() Date: Mon, 15 Nov 2021 17:58:37 +0100 Message-Id: <20211115165434.960178183@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165419.961798833@linuxfoundation.org> References: <20211115165419.961798833@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ziyang Xuan [ Upstream commit 0a5c26712f963f0500161a23e0ffff8d29f742ab ] When device_register() return failed, program will goto out_kfree_type to release 'cdev->device' by put_device(). That will call thermal_release() to free 'cdev'. But the follow-up processes access 'cdev' continually. That trggers the UAF bug. ==================================================================== BUG: KASAN: use-after-free in __thermal_cooling_device_register+0x75b/0xa90 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: dump_stack_lvl+0xe2/0x152 print_address_description.constprop.0+0x21/0x140 ? __thermal_cooling_device_register+0x75b/0xa90 kasan_report.cold+0x7f/0x11b ? __thermal_cooling_device_register+0x75b/0xa90 __thermal_cooling_device_register+0x75b/0xa90 ? memset+0x20/0x40 ? __sanitizer_cov_trace_pc+0x1d/0x50 ? __devres_alloc_node+0x130/0x180 devm_thermal_of_cooling_device_register+0x67/0xf0 max6650_probe.cold+0x557/0x6aa ...... Freed by task 258: kasan_save_stack+0x1b/0x40 kasan_set_track+0x1c/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x109/0x140 kfree+0x117/0x4c0 thermal_release+0xa0/0x110 device_release+0xa7/0x240 kobject_put+0x1ce/0x540 put_device+0x20/0x30 __thermal_cooling_device_register+0x731/0xa90 devm_thermal_of_cooling_device_register+0x67/0xf0 max6650_probe.cold+0x557/0x6aa [max6650] Do not use 'cdev' again after put_device() to fix the problem like doing in thermal_zone_device_register(). [dlezcano]: as requested by Rafael, change the affectation into two statements. Fixes: 584837618100 ("thermal/drivers/core: Use a char pointer for the cooling device name") Signed-off-by: Ziyang Xuan Reported-by: kernel test robot Link: https://lore.kernel.org/r/20211015024504.947520-1-william.xuanziyang@huawei.com Signed-off-by: Daniel Lezcano Signed-off-by: Sasha Levin --- drivers/thermal/thermal_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index d094ebbde0ed7..30134f49b037a 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -887,7 +887,7 @@ __thermal_cooling_device_register(struct device_node *np, { struct thermal_cooling_device *cdev; struct thermal_zone_device *pos = NULL; - int ret; + int id, ret; if (!ops || !ops->get_max_state || !ops->get_cur_state || !ops->set_cur_state) @@ -901,6 +901,7 @@ __thermal_cooling_device_register(struct device_node *np, if (ret < 0) goto out_kfree_cdev; cdev->id = ret; + id = ret; ret = dev_set_name(&cdev->device, "cooling_device%d", cdev->id); if (ret) @@ -944,8 +945,9 @@ __thermal_cooling_device_register(struct device_node *np, out_kfree_type: kfree(cdev->type); put_device(&cdev->device); + cdev = NULL; out_ida_remove: - ida_simple_remove(&thermal_cdev_ida, cdev->id); + ida_simple_remove(&thermal_cdev_ida, id); out_kfree_cdev: kfree(cdev); return ERR_PTR(ret); -- 2.33.0