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 835BDC6FD1C for ; Sat, 11 Mar 2023 16:14:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230453AbjCKQOD (ORCPT ); Sat, 11 Mar 2023 11:14:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230179AbjCKQOB (ORCPT ); Sat, 11 Mar 2023 11:14:01 -0500 Received: from m12.mail.163.com (m12.mail.163.com [220.181.12.199]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6EC4228E50; Sat, 11 Mar 2023 08:13:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=fz36A kXpYMaBUJI+NqgAwqVO9nDPS2Gc+hOC9+rtMto=; b=iun3BZKGbRyvtMGci4XWb 5+q8Bnul2sk1NAdC2sntb7J5eYYMFXYnV5s9M2WWjTkb5LKgRvfz8HGLLxTMmvM1 WmwmckcWV0Z87ib5gFa/ajIzlsc9WeQnP98326axnd5o6/iYzL+CTeVQtyRNUtrm +CwEsscXWEyf4ysZ5VGKZ8= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by zwqz-smtp-mta-g4-2 (Coremail) with SMTP id _____wAndn58qAxkIM8FDA--.21310S2; Sun, 12 Mar 2023 00:12:44 +0800 (CST) From: Zheng Wang To: gregkh@linuxfoundation.org Cc: p.zabel@pengutronix.de, biju.das.jz@bp.renesas.com, phil.edworthy@renesas.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, hackerzheng666@gmail.com, 1395428693sheep@gmail.com, alex000young@gmail.com, yoshihiro.shimoda.uh@renesas.com, Zheng Wang Subject: [PATCH v2] usb: gadget: udc: renesas_usb3: Fix use after free bug in renesas_usb3_remove due to race condition Date: Sun, 12 Mar 2023 00:12:42 +0800 Message-Id: <20230311161242.3773432-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: _____wAndn58qAxkIM8FDA--.21310S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7tF1DGryfJr47ArWxZFyDAwb_yoW8Gw13pF Z8KFW8Jr4rGFW0q39rGFykZF1rCF9rKry7ZFWxKws7uF1rG3y8tr92qa1j9F1xJFZ3Ar4F qa4Du340qay7u37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0ziaZXrUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/1tbiQh8vU1aEEn8ixQAAs5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In renesas_usb3_probe, &usb3->role_work is bound with renesas_usb3_role_work. renesas_usb3_start will be called to start the work. to make cleanup, there may be an unfinished work. The possible sequence is as follows: Fix it by canceling the work before cleanup in the renesas_usb3_remove CPU0 CPU1 |renesas_usb3_role_work renesas_usb3_remove | usb_role_switch_unregister | device_unregister | kfree(sw) | free usb3->role_sw | | usb_role_switch_set_role | //use usb3->role_sw Fixes: 39facfa01c9f ("usb: gadget: udc: renesas_usb3: Add register of usb role switch") Signed-off-by: Zheng Wang --- v2: - fix typo, use clearer commit message and only cancel the UAF-related work suggested by Yoshihiro Shimoda --- drivers/usb/gadget/udc/renesas_usb3.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c index bee6bceafc4f..a301af66bd91 100644 --- a/drivers/usb/gadget/udc/renesas_usb3.c +++ b/drivers/usb/gadget/udc/renesas_usb3.c @@ -2661,6 +2661,7 @@ static int renesas_usb3_remove(struct platform_device *pdev) debugfs_remove_recursive(usb3->dentry); device_remove_file(&pdev->dev, &dev_attr_role); + cancel_work_sync(&usb3->role_work); usb_role_switch_unregister(usb3->role_sw); usb_del_gadget_udc(&usb3->gadget); -- 2.25.1