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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 1CA0AC4360C for ; Thu, 26 Sep 2019 09:12:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E62DF222C3 for ; Thu, 26 Sep 2019 09:12:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569489171; bh=9T2cneHQ7XqSAIUOQrPR0ScATXba/YuqsElPghl9baI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wvs9YRS3fY0AOX+b9AaWTeQvsHoXgauKOqp2tqbzFnIt6D73Gp1bWI2H+Kwyibn9g olpMOUcnoOlp+2IUG6Q0+AOgpIlZYu3jdmENCUp8HB8u4go4ApMHGEyaeNgTiAO9fV 8kRiNfCDF/lFx3eMh7llbTYNYIlhK0EfXItL2tn4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730188AbfIZJMu (ORCPT ); Thu, 26 Sep 2019 05:12:50 -0400 Received: from mail-lj1-f193.google.com ([209.85.208.193]:37924 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729167AbfIZJMt (ORCPT ); Thu, 26 Sep 2019 05:12:49 -0400 Received: by mail-lj1-f193.google.com with SMTP id b20so1362309ljj.5; Thu, 26 Sep 2019 02:12:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bKDYWL5jP7ajoKT3dPjrbKASExuHF8+ZZfOI4omjdpc=; b=IYsAtosY9TeDfqjWQ3OdSKovIJC7JyzIUJ3egyLLFbb/mIhR6ifF9lz5to6+9r8iuB SNNd2/k6VCnrsJa8cVj/pNChRXjA7Eiyd32KtNY0zIH0yLKYSX50Z1o4R3RTPeoyAMgg qKbEXNlF1/+A0rNTzvf4vmNGfGPaOvycIt9ebOa1O7ck3E4a84gruQnrb/Tc8jXFb8li cPZXyS5ZulEMo5ua25Y7kpIGV/UACvw1eBubk1UKjG688KCPkvLvCM6s7kB3n2hulIJz Ko3JPgNH5FjNHpf8c6A8dRKZbrV0JaerEGLHq16uHQ2DKtRWSo71adW2KnVCeVjUxpfR Cm4g== X-Gm-Message-State: APjAAAUjqB0ynAxLoXe6i2DxB77sWGJ3Nhd6k8hLQmdbdjQK5Tw+G0v7 GJojAE8DjBZprHWHsCm4kNM= X-Google-Smtp-Source: APXvYqwaayLvoGLaMSOcgGVE5tNXXHFfJmLAnUyqQyYv+e5U1lunaclulcsNRdjRgsCcxuQNR5dbIQ== X-Received: by 2002:a2e:3902:: with SMTP id g2mr1844414lja.196.1569489167017; Thu, 26 Sep 2019 02:12:47 -0700 (PDT) Received: from xi.terra (c-51f1e055.07-184-6d6c6d4.bbcust.telenor.se. [85.224.241.81]) by smtp.gmail.com with ESMTPSA id u8sm446699lfb.36.2019.09.26.02.12.43 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 26 Sep 2019 02:12:45 -0700 (PDT) Received: from johan by xi.terra with local (Exim 4.92.2) (envelope-from ) id 1iDPpS-0006Qs-7F; Thu, 26 Sep 2019 11:12:50 +0200 From: Johan Hovold To: Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, Johan Hovold , stable Subject: [PATCH 1/4] USB: usblcd: fix I/O after disconnect Date: Thu, 26 Sep 2019 11:12:25 +0200 Message-Id: <20190926091228.24634-7-johan@kernel.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190926091228.24634-1-johan@kernel.org> References: <20190926091228.24634-1-johan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Make sure to stop all I/O on disconnect by adding a disconnected flag which is used to prevent new I/O from being started and by stopping all ongoing I/O before returning. This also fixes a potential use-after-free on driver unbind in case the driver data is freed before the completion handler has run. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable # 7bbe990c989e Signed-off-by: Johan Hovold --- drivers/usb/misc/usblcd.c | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/drivers/usb/misc/usblcd.c b/drivers/usb/misc/usblcd.c index 9ba4a4e68d91..aa982d3ca36b 100644 --- a/drivers/usb/misc/usblcd.c +++ b/drivers/usb/misc/usblcd.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -57,6 +58,8 @@ struct usb_lcd { using up all RAM */ struct usb_anchor submitted; /* URBs to wait for before suspend */ + struct rw_semaphore io_rwsem; + unsigned long disconnected:1; }; #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) @@ -142,6 +145,13 @@ static ssize_t lcd_read(struct file *file, char __user * buffer, dev = file->private_data; + down_read(&dev->io_rwsem); + + if (dev->disconnected) { + retval = -ENODEV; + goto out_up_io; + } + /* do a blocking bulk read to get data from the device */ retval = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, @@ -158,6 +168,9 @@ static ssize_t lcd_read(struct file *file, char __user * buffer, retval = bytes_read; } +out_up_io: + up_read(&dev->io_rwsem); + return retval; } @@ -237,11 +250,18 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, if (r < 0) return -EINTR; + down_read(&dev->io_rwsem); + + if (dev->disconnected) { + retval = -ENODEV; + goto err_up_io; + } + /* create a urb, and a buffer for it, and copy the data to the urb */ urb = usb_alloc_urb(0, GFP_KERNEL); if (!urb) { retval = -ENOMEM; - goto err_no_buf; + goto err_up_io; } buf = usb_alloc_coherent(dev->udev, count, GFP_KERNEL, @@ -278,6 +298,7 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, the USB core will eventually free it entirely */ usb_free_urb(urb); + up_read(&dev->io_rwsem); exit: return count; error_unanchor: @@ -285,7 +306,8 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, error: usb_free_coherent(dev->udev, count, buf, urb->transfer_dma); usb_free_urb(urb); -err_no_buf: +err_up_io: + up_read(&dev->io_rwsem); up(&dev->limit_sem); return retval; } @@ -325,6 +347,7 @@ static int lcd_probe(struct usb_interface *interface, kref_init(&dev->kref); sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); + init_rwsem(&dev->io_rwsem); init_usb_anchor(&dev->submitted); dev->udev = usb_get_dev(interface_to_usbdev(interface)); @@ -422,6 +445,12 @@ static void lcd_disconnect(struct usb_interface *interface) /* give back our minor */ usb_deregister_dev(interface, &lcd_class); + down_write(&dev->io_rwsem); + dev->disconnected = 1; + up_write(&dev->io_rwsem); + + usb_kill_anchored_urbs(&dev->submitted); + /* decrement our usage count */ kref_put(&dev->kref, lcd_delete); -- 2.23.0