From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964816AbcKNCdx (ORCPT ); Sun, 13 Nov 2016 21:33:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:47351 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938683AbcKNCdh (ORCPT ); Sun, 13 Nov 2016 21:33:37 -0500 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, "roswest" , "Greg Kroah-Hartman" , "Alan Stern" Date: Mon, 14 Nov 2016 00:14:20 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 165/346] USB: validate wMaxPacketValue entries in endpoint descriptors In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 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 List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.39-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit aed9d65ac3278d4febd8665bd7db59ef53e825fe upstream. Erroneous or malicious endpoint descriptors may have non-zero bits in reserved positions, or out-of-bounds values. This patch helps prevent these from causing problems by bounds-checking the wMaxPacketValue entries in endpoint descriptors and capping the values at the maximum allowed. This issue was first discovered and tests were conducted by Jake Lamberson , an intern working for Rosie Hall. Signed-off-by: Alan Stern Reported-by: roswest Tested-by: roswest Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.16: drop the USB_SPEED_SUPER_PLUS case] Signed-off-by: Ben Hutchings --- drivers/usb/core/config.c | 66 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 63 insertions(+), 3 deletions(-) --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -142,6 +142,31 @@ static void usb_parse_ss_endpoint_compan } } +static const unsigned short low_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 8, + [USB_ENDPOINT_XFER_ISOC] = 0, + [USB_ENDPOINT_XFER_BULK] = 0, + [USB_ENDPOINT_XFER_INT] = 8, +}; +static const unsigned short full_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 64, + [USB_ENDPOINT_XFER_ISOC] = 1023, + [USB_ENDPOINT_XFER_BULK] = 64, + [USB_ENDPOINT_XFER_INT] = 64, +}; +static const unsigned short high_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 64, + [USB_ENDPOINT_XFER_ISOC] = 1024, + [USB_ENDPOINT_XFER_BULK] = 512, + [USB_ENDPOINT_XFER_INT] = 1023, +}; +static const unsigned short super_speed_maxpacket_maxes[4] = { + [USB_ENDPOINT_XFER_CONTROL] = 512, + [USB_ENDPOINT_XFER_ISOC] = 1024, + [USB_ENDPOINT_XFER_BULK] = 1024, + [USB_ENDPOINT_XFER_INT] = 1024, +}; + static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum, int asnum, struct usb_host_interface *ifp, int num_ep, unsigned char *buffer, int size) @@ -150,6 +175,8 @@ static int usb_parse_endpoint(struct dev struct usb_endpoint_descriptor *d; struct usb_host_endpoint *endpoint; int n, i, j, retval; + unsigned int maxp; + const unsigned short *maxpacket_maxes; d = (struct usb_endpoint_descriptor *) buffer; buffer += d->bLength; @@ -256,6 +283,41 @@ static int usb_parse_endpoint(struct dev endpoint->desc.wMaxPacketSize = cpu_to_le16(8); } + /* Validate the wMaxPacketSize field */ + maxp = usb_endpoint_maxp(&endpoint->desc); + + /* Find the highest legal maxpacket size for this endpoint */ + i = 0; /* additional transactions per microframe */ + switch (to_usb_device(ddev)->speed) { + case USB_SPEED_LOW: + maxpacket_maxes = low_speed_maxpacket_maxes; + break; + case USB_SPEED_FULL: + maxpacket_maxes = full_speed_maxpacket_maxes; + break; + case USB_SPEED_HIGH: + /* Bits 12..11 are allowed only for HS periodic endpoints */ + if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) { + i = maxp & (BIT(12) | BIT(11)); + maxp &= ~i; + } + /* fallthrough */ + default: + maxpacket_maxes = high_speed_maxpacket_maxes; + break; + case USB_SPEED_SUPER: + maxpacket_maxes = super_speed_maxpacket_maxes; + break; + } + j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)]; + + if (maxp > j) { + dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n", + cfgno, inum, asnum, d->bEndpointAddress, maxp, j); + maxp = j; + endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp); + } + /* * Some buggy high speed devices have bulk endpoints using * maxpacket sizes other than 512. High speed HCDs may not @@ -263,9 +325,6 @@ static int usb_parse_endpoint(struct dev */ if (to_usb_device(ddev)->speed == USB_SPEED_HIGH && usb_endpoint_xfer_bulk(d)) { - unsigned maxp; - - maxp = usb_endpoint_maxp(&endpoint->desc) & 0x07ff; if (maxp != 512) dev_warn(ddev, "config %d interface %d altsetting %d " "bulk endpoint 0x%X has invalid maxpacket %d\n",