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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 3802FC43331 for ; Mon, 11 Nov 2019 19:03:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B9AA22459 for ; Mon, 11 Nov 2019 19:03:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573499019; bh=G8BUvuGqCsCb7yjKvZ8Fd+KEP4P+4gbsycA/xzIZ9ys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LZ8nZGJMUDH83tCSLfoIvYNZPlJsYSwch1q5h5mWYmcu0livcy0ftao1FL8PnaSDa GKVJCWLTpBH9wk7vnI9GphzyYm28mBBy9VXTHAJ4CAzejykMRQbKdK2INd5G3fweps QRMG7PCOd5Z9+5KASOWNR4SHlQNG4bQJZPuCMxFg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729804AbfKKSo7 (ORCPT ); Mon, 11 Nov 2019 13:44:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:36838 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729801AbfKKSo7 (ORCPT ); Mon, 11 Nov 2019 13:44:59 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 13D4420674; Mon, 11 Nov 2019 18:44:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573497899; bh=G8BUvuGqCsCb7yjKvZ8Fd+KEP4P+4gbsycA/xzIZ9ys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DONU9sxWjjwJRrkP7H7xfK9+9LA7BbfQfUDZvuVjfwNyia4+MacpUmhfyYkZqzOkS 9HGr87F1pEpdzXhtT5OciGYmXo1loTjVr73B1UVNP4S4F2rC6dZKdYB/74TBBlkE2e Xs9A9fxyblMcCNtvVnCLyvevOS1SccuRm3ToBMjA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chandana Kishori Chiluveru , Felipe Balbi , Sasha Levin Subject: [PATCH 4.19 091/125] usb: gadget: composite: Fix possible double free memory bug Date: Mon, 11 Nov 2019 19:28:50 +0100 Message-Id: <20191111181452.115930114@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191111181438.945353076@linuxfoundation.org> References: <20191111181438.945353076@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Chandana Kishori Chiluveru [ Upstream commit 1c20c89b0421b52b2417bb0f62a611bc669eda1d ] composite_dev_cleanup call from the failure of configfs_composite_bind frees up the cdev->os_desc_req and cdev->req. If the previous calls of bind and unbind is successful these will carry stale values. Consider the below sequence of function calls: configfs_composite_bind() composite_dev_prepare() - Allocate cdev->req, cdev->req->buf composite_os_desc_req_prepare() - Allocate cdev->os_desc_req, cdev->os_desc_req->buf configfs_composite_unbind() composite_dev_cleanup() - free the cdev->os_desc_req->buf and cdev->req->buf Next composition switch configfs_composite_bind() - If it fails goto err_comp_cleanup will call the composite_dev_cleanup() function composite_dev_cleanup() - calls kfree up with the stale values of cdev->req->buf and cdev->os_desc_req from the previous configfs_composite_bind call. The free call on these stale values leads to double free. Hence, Fix this issue by setting request and buffer pointer to NULL after kfree. Signed-off-by: Chandana Kishori Chiluveru Signed-off-by: Felipe Balbi Signed-off-by: Sasha Levin --- drivers/usb/gadget/composite.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c index dfcabadeed01b..33115e19756c6 100644 --- a/drivers/usb/gadget/composite.c +++ b/drivers/usb/gadget/composite.c @@ -2156,14 +2156,18 @@ void composite_dev_cleanup(struct usb_composite_dev *cdev) usb_ep_dequeue(cdev->gadget->ep0, cdev->os_desc_req); kfree(cdev->os_desc_req->buf); + cdev->os_desc_req->buf = NULL; usb_ep_free_request(cdev->gadget->ep0, cdev->os_desc_req); + cdev->os_desc_req = NULL; } if (cdev->req) { if (cdev->setup_pending) usb_ep_dequeue(cdev->gadget->ep0, cdev->req); kfree(cdev->req->buf); + cdev->req->buf = NULL; usb_ep_free_request(cdev->gadget->ep0, cdev->req); + cdev->req = NULL; } cdev->next_string_id = 0; device_remove_file(&cdev->gadget->dev, &dev_attr_suspended); -- 2.20.1