From patchwork Tue Apr 16 11:16:19 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 236942 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 1C8112C011C for ; Tue, 16 Apr 2013 21:16:31 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1US3s6-0000Ye-Q9; Tue, 16 Apr 2013 11:16:22 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1US3s4-0000YZ-Tq for kernel-team@lists.ubuntu.com; Tue, 16 Apr 2013 11:16:20 +0000 Received: from bl20-140-10.dsl.telepac.pt ([2.81.140.10] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1US3s4-00034Z-KX for kernel-team@lists.ubuntu.com; Tue, 16 Apr 2013 11:16:20 +0000 From: Luis Henriques To: kernel-team@lists.ubuntu.com Subject: [Lucid CVE-2013-1860] USB: cdc-wdm: fix buffer overflow Date: Tue, 16 Apr 2013 12:16:19 +0100 Message-Id: <1366110979-15016-1-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 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 From: Oliver Neukum CVE-2013-1860 BugLink: http://bugs.launchpad.net/bugs/1156784 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 CC: stable@kernel.org Signed-off-by: Greg Kroah-Hartman (back ported from commit c0f5ecee4e741667b2493c742b60b6218d40b3aa) Signed-off-by: Luis Henriques Acked-by: Andy Whitcroft --- drivers/usb/class/cdc-wdm.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 37f2899..6ca1363 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -52,7 +52,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_READ 4 #define WDM_INT_STALL 5 #define WDM_POLL_RUNNING 6 - +#define WDM_OVERFLOW 10 #define WDM_MAX 16 @@ -115,6 +115,7 @@ 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); @@ -144,9 +145,17 @@ 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; + } + } wake_up(&desc->wait); set_bit(WDM_READ, &desc->flags); @@ -398,6 +407,11 @@ 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)) { @@ -440,6 +454,7 @@ 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); @@ -844,6 +859,7 @@ static int wdm_post_reset(struct usb_interface *intf) struct wdm_device *desc = usb_get_intfdata(intf); int rv; + clear_bit(WDM_OVERFLOW, &desc->flags); rv = recover_from_urb_loss(desc); mutex_unlock(&desc->plock); return 0;