From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755962Ab0C3XKH (ORCPT ); Tue, 30 Mar 2010 19:10:07 -0400 Received: from kroah.org ([198.145.64.141]:48662 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755725Ab0C3XJ0 (ORCPT ); Tue, 30 Mar 2010 19:09:26 -0400 X-Mailbox-Line: From linux@linux.site Tue Mar 30 15:50:09 2010 Message-Id: <20100330225008.999625477@linux.site> User-Agent: quilt/0.47-14.9 Date: Tue, 30 Mar 2010 15:49:04 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Alan Stern , Greg Kroah-Hartman Subject: [44/45] USB: fix usbfs regression In-Reply-To: <20100330230410.GA28712@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Alan Stern commit 7152b592593b9d48b33f8997b1dfd6df9143f7ec upstream. This patch (as1352) fixes a bug in the way isochronous input data is returned to userspace for usbfs transfers. The entire buffer must be copied, not just the first actual_length bytes, because the individual packets will be discontiguous if any of them are short. Reported-by: Markus Rechberger Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1123,6 +1123,13 @@ static int proc_do_submiturb(struct dev_ free_async(as); return -ENOMEM; } + /* Isochronous input data may end up being discontiguous + * if some of the packets are short. Clear the buffer so + * that the gaps don't leak kernel data to userspace. + */ + if (is_in && uurb->type == USBDEVFS_URB_TYPE_ISO) + memset(as->urb->transfer_buffer, 0, + uurb->buffer_length); } as->urb->dev = ps->dev; as->urb->pipe = (uurb->type << 30) | @@ -1224,10 +1231,14 @@ static int processcompl(struct async *as void __user *addr = as->userurb; unsigned int i; - if (as->userbuffer && urb->actual_length) - if (copy_to_user(as->userbuffer, urb->transfer_buffer, - urb->actual_length)) + if (as->userbuffer && urb->actual_length) { + if (urb->number_of_packets > 0) /* Isochronous */ + i = urb->transfer_buffer_length; + else /* Non-Isoc */ + i = urb->actual_length; + if (copy_to_user(as->userbuffer, urb->transfer_buffer, i)) goto err_out; + } if (put_user(as->status, &userurb->status)) goto err_out; if (put_user(urb->actual_length, &userurb->actual_length))