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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 AEE4BC43603 for ; Tue, 17 Dec 2019 01:00:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CFE2206D3 for ; Tue, 17 Dec 2019 01:00:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727986AbfLQBAi (ORCPT ); Mon, 16 Dec 2019 20:00:38 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34626 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726591AbfLQAvd (ORCPT ); Mon, 16 Dec 2019 19:51:33 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ih15G-0003Jp-8H; Tue, 17 Dec 2019 00:51:30 +0000 Received: from ben by deadeye with local (Exim 4.93-RC7) (envelope-from ) id 1ih15F-0005Sl-KB; Tue, 17 Dec 2019 00:51:29 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Johan Hovold" , "Greg Kroah-Hartman" Date: Tue, 17 Dec 2019 00:45:53 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 019/136] USB: adutux: fix NULL-derefs on disconnect In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.80-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold commit b2fa7baee744fde746c17bc1860b9c6f5c2eebb7 upstream. The driver was using its struct usb_device pointer as an inverted disconnected flag, but was setting it to NULL before making sure all completion handlers had run. This could lead to a NULL-pointer dereference in a number of dev_dbg statements in the completion handlers which relies on said pointer. The pointer was also dereferenced unconditionally in a dev_dbg statement release() something which would lead to a NULL-deref whenever a device was disconnected before the final character-device close if debugging was enabled. Fix this by unconditionally stopping all I/O and preventing resubmissions by poisoning the interrupt URBs at disconnect and using a dedicated disconnected flag. This also makes sure that all I/O has completed by the time the disconnect callback returns. Fixes: 1ef37c6047fe ("USB: adutux: remove custom debug macro and module parameter") Fixes: 66d4bc30d128 ("USB: adutux: remove custom debug macro") Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20190925092913.8608-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/usb/misc/adutux.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) --- a/drivers/usb/misc/adutux.c +++ b/drivers/usb/misc/adutux.c @@ -80,6 +80,7 @@ struct adu_device { char serial_number[8]; int open_count; /* number of times this port has been opened */ + unsigned long disconnected:1; char *read_buffer_primary; int read_buffer_length; @@ -121,7 +122,7 @@ static void adu_abort_transfers(struct a { unsigned long flags; - if (dev->udev == NULL) + if (dev->disconnected) return; /* shutdown transfer */ @@ -244,7 +245,7 @@ static int adu_open(struct inode *inode, } dev = usb_get_intfdata(interface); - if (!dev || !dev->udev) { + if (!dev) { retval = -ENODEV; goto exit_no_device; } @@ -327,7 +328,7 @@ static int adu_release(struct inode *ino } adu_release_internal(dev); - if (dev->udev == NULL) { + if (dev->disconnected) { /* the device was unplugged before the file was released */ if (!dev->open_count) /* ... and we're the last user */ adu_delete(dev); @@ -356,7 +357,7 @@ static ssize_t adu_read(struct file *fil return -ERESTARTSYS; /* verify that the device wasn't unplugged */ - if (dev->udev == NULL) { + if (dev->disconnected) { retval = -ENODEV; pr_err("No device or device unplugged %d\n", retval); goto exit; @@ -521,7 +522,7 @@ static ssize_t adu_write(struct file *fi goto exit_nolock; /* verify that the device wasn't unplugged */ - if (dev->udev == NULL) { + if (dev->disconnected) { retval = -ENODEV; pr_err("No device or device unplugged %d\n", retval); goto exit; @@ -801,11 +802,14 @@ static void adu_disconnect(struct usb_in usb_deregister_dev(interface, &adu_class); + usb_poison_urb(dev->interrupt_in_urb); + usb_poison_urb(dev->interrupt_out_urb); + mutex_lock(&adutux_mutex); usb_set_intfdata(interface, NULL); mutex_lock(&dev->mtx); /* not interruptible */ - dev->udev = NULL; /* poison */ + dev->disconnected = 1; mutex_unlock(&dev->mtx); /* if the device is not opened, then we clean up right now */