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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 0083DC432C0 for ; Tue, 26 Nov 2019 15:49:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5F5E2071E for ; Tue, 26 Nov 2019 15:49:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727560AbfKZPtR (ORCPT ); Tue, 26 Nov 2019 10:49:17 -0500 Received: from mga04.intel.com ([192.55.52.120]:17992 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727309AbfKZPtR (ORCPT ); Tue, 26 Nov 2019 10:49:17 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Nov 2019 07:49:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,246,1571727600"; d="scan'208";a="217184051" Received: from kuha.fi.intel.com ([10.237.72.53]) by fmsmga001.fm.intel.com with SMTP; 26 Nov 2019 07:49:14 -0800 Received: by kuha.fi.intel.com (sSMTP sendmail emulation); Tue, 26 Nov 2019 17:49:13 +0200 Date: Tue, 26 Nov 2019 17:49:13 +0200 From: Heikki Krogerus To: Wen Yang Cc: Greg Kroah-Hartman , Hans de Goede , Chunfeng Yun , Suzuki K Poulose , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: roles: fix a potential use after free Message-ID: <20191126154913.GB6428@kuha.fi.intel.com> References: <20191124142236.25671-1-wenyang@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191124142236.25671-1-wenyang@linux.alibaba.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Sun, Nov 24, 2019 at 10:22:36PM +0800, Wen Yang wrote: > Free the sw structure only after we are done using it. > This patch just moves the put_device() down a bit to avoid the > use after free. > > Fixes: 5c54fcac9a9d ("usb: roles: Take care of driver module reference counting") > Signed-off-by: Wen Yang > Cc: Heikki Krogerus > Cc: Hans de Goede > Cc: Greg Kroah-Hartman > Cc: Chunfeng Yun > Cc: Suzuki K Poulose > Cc: linux-usb@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/usb/roles/class.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c > index 8273126..63a00ff 100644 > --- a/drivers/usb/roles/class.c > +++ b/drivers/usb/roles/class.c > @@ -169,8 +169,8 @@ struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *fwnode) > void usb_role_switch_put(struct usb_role_switch *sw) > { > if (!IS_ERR_OR_NULL(sw)) { > - put_device(&sw->dev); > module_put(sw->dev.parent->driver->owner); > + put_device(&sw->dev); > } > } > EXPORT_SYMBOL_GPL(usb_role_switch_put); > -- > 1.8.3.1 -- heikki