From patchwork Mon Oct 24 11:27:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 9022 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp441410wru; Mon, 24 Oct 2022 06:05:53 -0700 (PDT) X-Google-Smtp-Source: AMsMyM74N72RPNBF11GAn3YupzY71r58OANsGtiUd5pFgDobak3M8fRgBrVpLTkGnaxstZCgkoWj X-Received: by 2002:a17:90b:350d:b0:20d:5438:f594 with SMTP id ls13-20020a17090b350d00b0020d5438f594mr75568585pjb.216.1666616752678; Mon, 24 Oct 2022 06:05:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1666616752; cv=none; d=google.com; s=arc-20160816; b=R59d3QtsKw+VSsPxzXNS/hkDRGdAsyil/gRj1mni6pNtHZ36iWIFGUrGx9HjEh+LXt f4DZv7fwpUNTyv+9CAOYegMqFX6P/oB65ZXgDVAdwOz02uwMcBl6OZXGhnwwEvDwgPm0 gGZCi/O10QYYBGiEwNnnAFjTvEl78NeRN/jNKdJdMJ4bo1czYkA8QNFBqMPOS0ZXByXz Odpo1nR+vVP+850WpDsdmtuCqXqrFKAomNfnu/bMnjy03TkgtqUOLAUvsbF4WOIe0p5z qjnpeyZTKsxUgbSEcVYMtUa82J/HUgtt2v+EEzZARg4wtbOio2w0CGvCf2ySHT3b9/YU iGBw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=R1nuOcBaVMow6jMJ7eiDkRk+iYDx50eTA4qclaF4Ud4=; b=RowbUE7gKrBSSH/FOi6XJKLfa/Q2BPPYpSprxFNTDZukD2q3eGP/G7A+Bowdg1C5Qc VmxIO5gyFrZVGxEdYk0KhemXcGt8+CduCfBxfZdWknHCohtrQh5damOsNEKo2vij3n/U hwYh3kDgZ/wkgLpqPcar9SUDm6pAawaa1LJLeKZ/k9b5L7jJ+4DKzApS3aZYjlo4X729 PxBOyrFE5EGVoduMuKZS5EFY3S3/bingJiCPpfbET08eMiM7zaxg1YnefbMhVKZLSG7S ZXLMI89lqsZcgCDCZ8b6XRjgzdC4JLPEXfdOf995s+weO/TmwgyyQH1jySoiUd9PpvXU kR6A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=mhxdBmLP; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id e23-20020a635017000000b0045a6c6c559bsi34755489pgb.305.2022.10.24.06.05.26; Mon, 24 Oct 2022 06:05:52 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=mhxdBmLP; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235445AbiJXNEs (ORCPT + 99 others); Mon, 24 Oct 2022 09:04:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235049AbiJXNBK (ORCPT ); Mon, 24 Oct 2022 09:01:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69F2B2870B; Mon, 24 Oct 2022 05:19:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8204C6131A; Mon, 24 Oct 2022 12:18:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 970B2C433C1; Mon, 24 Oct 2022 12:18:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666613898; bh=+xNnPHy9Ia7x9ClVvk0qMD1ZQWrB9NkkQ9bqD48pXi4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mhxdBmLPkmxhX6PIqiv7glFVNKh63Ks94K/7QeWk+NcM6yIT5lyAbB+0xXVCR0SZ1 TBhidGle/lieDPbapm5hxmMYrZ/dtkSGAG9nXyor7FhYJFgX/ChfMlntX1homxfRSE pruwFo16cTRCEYAmHR6b+umLXP91itxOnawuN75Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hyunwoo Kim , Helge Deller Subject: [PATCH 5.10 048/390] fbdev: smscufx: Fix use-after-free in ufx_ops_open() Date: Mon, 24 Oct 2022 13:27:25 +0200 Message-Id: <20221024113024.680384175@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113022.510008560@linuxfoundation.org> References: <20221024113022.510008560@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1747574328404918786?= X-GMAIL-MSGID: =?utf-8?q?1747574328404918786?= From: Hyunwoo Kim commit 5610bcfe8693c02e2e4c8b31427f1bdbdecc839c upstream. A race condition may occur if the user physically removes the USB device while calling open() for this device node. This is a race condition between the ufx_ops_open() function and the ufx_usb_disconnect() function, which may eventually result in UAF. So, add a mutex to the ufx_ops_open() and ufx_usb_disconnect() functions to avoid race contidion of krefs. Signed-off-by: Hyunwoo Kim Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman --- drivers/video/fbdev/smscufx.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/drivers/video/fbdev/smscufx.c +++ b/drivers/video/fbdev/smscufx.c @@ -137,6 +137,8 @@ static int ufx_submit_urb(struct ufx_dat static int ufx_alloc_urb_list(struct ufx_data *dev, int count, size_t size); static void ufx_free_urb_list(struct ufx_data *dev); +static DEFINE_MUTEX(disconnect_mutex); + /* reads a control register */ static int ufx_reg_read(struct ufx_data *dev, u32 index, u32 *data) { @@ -1070,9 +1072,13 @@ static int ufx_ops_open(struct fb_info * if (user == 0 && !console) return -EBUSY; + mutex_lock(&disconnect_mutex); + /* If the USB device is gone, we don't accept new opens */ - if (dev->virtualized) + if (dev->virtualized) { + mutex_unlock(&disconnect_mutex); return -ENODEV; + } dev->fb_count++; @@ -1096,6 +1102,8 @@ static int ufx_ops_open(struct fb_info * pr_debug("open /dev/fb%d user=%d fb_info=%p count=%d", info->node, user, info, dev->fb_count); + mutex_unlock(&disconnect_mutex); + return 0; } @@ -1740,6 +1748,8 @@ static void ufx_usb_disconnect(struct us { struct ufx_data *dev; + mutex_lock(&disconnect_mutex); + dev = usb_get_intfdata(interface); pr_debug("USB disconnect starting\n"); @@ -1760,6 +1770,8 @@ static void ufx_usb_disconnect(struct us kref_put(&dev->kref, ufx_free); /* consider ufx_data freed */ + + mutex_unlock(&disconnect_mutex); } static struct usb_driver ufx_driver = {