From patchwork Thu Mar 16 15:55:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheng Wang X-Patchwork-Id: 664983 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 B8685C6FD19 for ; Thu, 16 Mar 2023 15:55:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231345AbjCPPzy (ORCPT ); Thu, 16 Mar 2023 11:55:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231163AbjCPPzy (ORCPT ); Thu, 16 Mar 2023 11:55:54 -0400 Received: from m12.mail.163.com (m12.mail.163.com [220.181.12.196]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1508C34C31; Thu, 16 Mar 2023 08:55:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=XxqVP aMaesg3WKkTgax8wepxeqRRyKUw6FM6YPKmWUA=; b=KfCO3cFVY0ne3STL3Tbqe cyuuuvhGRR9BbJnbgW8hjq57QYNBv6l7MJ46adrUHvRvePFpPF4tVsutl7DrTzO1 PeTGhIxUdxu0neArJD0zAdXXIYle5Pa7CWfHZu4QMJ9gS51wWrVlPTRpbK+cWXEe CpaFy8ttV8JucvNqTEpHCo= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by zwqz-smtp-mta-g4-4 (Coremail) with SMTP id _____wC3vsbiOxNkJ7PVAA--.51531S2; Thu, 16 Mar 2023 23:55:15 +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 v4] usb: gadget: udc: renesas_usb3: Fix use after free bug in renesas_usb3_remove due to race condition Date: Thu, 16 Mar 2023 23:55:13 +0800 Message-Id: <20230316155513.1564746-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: _____wC3vsbiOxNkJ7PVAA--.51531S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7tF1DGryfJr47ArWxZFyDAwb_yoW8AFy5pF WUGFW5Ar4rJFWqq3y7GFykZF1rCF9rKry7ZFW7tw4xuF1rG3y8tryIqa1jkF1xJFZYyF4F q3WDu340qa47u37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zi-eOJUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/1tbiGgc0U1aEEmZOSwAAsZ Precedence: bulk List-ID: X-Mailing-List: linux-usb@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. If we remove the driver which will call usbhs_remove, 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") Reviewed-by: Yoshihiro Shimoda Signed-off-by: Zheng Wang Reviewed-by: Yoshihiro Shimoda --- v4: - and Reviewed-by label and resubmit v4 suggested by Greg KH v3: - modify the commit message to make it clearer suggested by Yoshihiro Shimoda 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);