From patchwork Tue Mar 26 15:18:34 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 231272 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id B77AD2C00A5 for ; Wed, 27 Mar 2013 02:21:54 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UKVh4-0007EC-Vp; Tue, 26 Mar 2013 15:21:46 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UKVh0-00077a-FW for kernel-team@lists.ubuntu.com; Tue, 26 Mar 2013 15:21:42 +0000 Received: from bl20-143-66.dsl.telepac.pt ([2.81.143.66] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UKVgz-0004aV-VA; Tue, 26 Mar 2013 15:21:42 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 015/150] USB: cdc-wdm: fix buffer overflow Date: Tue, 26 Mar 2013 15:18:34 +0000 Message-Id: <1364311249-14454-16-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1364311249-14454-1-git-send-email-luis.henriques@canonical.com> References: <1364311249-14454-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Cc: Greg Kroah-Hartman , Oliver Neukum X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.5.7.9 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Oliver Neukum commit c0f5ecee4e741667b2493c742b60b6218d40b3aa upstream. The buffer for responses must not overflow. If this would happen, set a flag, drop the data and return an error after user space has read all remaining data. Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman Signed-off-by: Luis Henriques --- drivers/usb/class/cdc-wdm.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 3cc771e..97c1d8e 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -81,6 +81,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_RESPONDING 7 #define WDM_SUSPENDING 8 #define WDM_RESETTING 9 +#define WDM_OVERFLOW 10 #define WDM_MAX 16 @@ -180,6 +181,7 @@ static void wdm_in_callback(struct urb *urb) { struct wdm_device *desc = urb->context; int status = urb->status; + int length = urb->actual_length; spin_lock(&desc->iuspin); clear_bit(WDM_RESPONDING, &desc->flags); @@ -210,9 +212,17 @@ static void wdm_in_callback(struct urb *urb) } desc->rerr = status; - desc->reslength = urb->actual_length; - memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength); - desc->length += desc->reslength; + if (length + desc->length > desc->wMaxCommand) { + /* The buffer would overflow */ + set_bit(WDM_OVERFLOW, &desc->flags); + } else { + /* we may already be in overflow */ + if (!test_bit(WDM_OVERFLOW, &desc->flags)) { + memmove(desc->ubuf + desc->length, desc->inbuf, length); + desc->length += length; + desc->reslength = length; + } + } skip_error: wake_up(&desc->wait); @@ -460,6 +470,11 @@ retry: rv = -ENODEV; goto err; } + if (test_bit(WDM_OVERFLOW, &desc->flags)) { + clear_bit(WDM_OVERFLOW, &desc->flags); + rv = -ENOBUFS; + goto err; + } i++; if (file->f_flags & O_NONBLOCK) { if (!test_bit(WDM_READ, &desc->flags)) { @@ -503,6 +518,7 @@ retry: spin_unlock_irq(&desc->iuspin); goto retry; } + if (!desc->reslength) { /* zero length read */ dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__); clear_bit(WDM_READ, &desc->flags); @@ -1029,6 +1045,7 @@ static int wdm_post_reset(struct usb_interface *intf) struct wdm_device *desc = wdm_find_device(intf); int rv; + clear_bit(WDM_OVERFLOW, &desc->flags); clear_bit(WDM_RESETTING, &desc->flags); rv = recover_from_urb_loss(desc); mutex_unlock(&desc->wlock);