From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:34042 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753887AbeA2UMG (ORCPT ); Mon, 29 Jan 2018 15:12:06 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Secunia Research , Shuah Khan Subject: [PATCH 4.4 02/74] usbip: prevent vhci_hcd driver from leaking a socket pointer address Date: Mon, 29 Jan 2018 13:56:07 +0100 Message-Id: <20180129123847.617716392@linuxfoundation.org> In-Reply-To: <20180129123847.507563674@linuxfoundation.org> References: <20180129123847.507563674@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shuah Khan commit 2f2d0088eb93db5c649d2a5e34a3800a8a935fc5 upstream. When a client has a USB device attached over IP, the vhci_hcd driver is locally leaking a socket pointer address via the /sys/devices/platform/vhci_hcd/status file (world-readable) and in debug output when "usbip --debug port" is run. Fix it to not leak. The socket pointer address is not used at the moment and it was made visible as a convenient way to find IP address from socket pointer address by looking up /proc/net/{tcp,tcp6}. As this opens a security hole, the fix replaces socket pointer address with sockfd. Reported-by: Secunia Research Signed-off-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman --- drivers/usb/usbip/usbip_common.h | 1 + drivers/usb/usbip/vhci_sysfs.c | 25 +++++++++++++++---------- tools/usb/usbip/libsrc/vhci_driver.c | 8 ++++---- 3 files changed, 20 insertions(+), 14 deletions(-) --- a/drivers/usb/usbip/usbip_common.h +++ b/drivers/usb/usbip/usbip_common.h @@ -261,6 +261,7 @@ struct usbip_device { /* lock for status */ spinlock_t lock; + int sockfd; struct socket *tcp_socket; struct task_struct *tcp_rx; --- a/drivers/usb/usbip/vhci_sysfs.c +++ b/drivers/usb/usbip/vhci_sysfs.c @@ -39,16 +39,20 @@ static ssize_t status_show(struct device /* * output example: - * prt sta spd dev socket local_busid - * 000 004 000 000 c5a7bb80 1-2.3 - * 001 004 000 000 d8cee980 2-3.4 + * port sta spd dev sockfd local_busid + * 0000 004 000 00000000 000003 1-2.3 + * 0001 004 000 00000000 000004 2-3.4 * - * IP address can be retrieved from a socket pointer address by looking - * up /proc/net/{tcp,tcp6}. Also, a userland program may remember a - * port number and its peer IP address. + * Output includes socket fd instead of socket pointer address to + * avoid leaking kernel memory address in: + * /sys/devices/platform/vhci_hcd.0/status and in debug output. + * The socket pointer address is not used at the moment and it was + * made visible as a convenient way to find IP address from socket + * pointer address by looking up /proc/net/{tcp,tcp6}. As this opens + * a security hole, the change is made to use sockfd instead. */ out += sprintf(out, - "prt sta spd bus dev socket local_busid\n"); + "prt sta spd bus dev sockfd local_busid\n"); for (i = 0; i < VHCI_NPORTS; i++) { struct vhci_device *vdev = port_to_vdev(i); @@ -60,11 +64,11 @@ static ssize_t status_show(struct device out += sprintf(out, "%03u %08x ", vdev->speed, vdev->devid); out += sprintf(out, "%16p ", vdev->ud.tcp_socket); + out += sprintf(out, "%06u", vdev->ud.sockfd); out += sprintf(out, "%s", dev_name(&vdev->udev->dev)); - } else { - out += sprintf(out, "000 000 000 0000000000000000 0-0"); - } + } else + out += sprintf(out, "000 000 000 000000 0-0"); out += sprintf(out, "\n"); spin_unlock(&vdev->ud.lock); @@ -223,6 +227,7 @@ static ssize_t store_attach(struct devic vdev->devid = devid; vdev->speed = speed; + vdev->ud.sockfd = sockfd; vdev->ud.tcp_socket = socket; vdev->ud.status = VDEV_ST_NOTASSIGNED; --- a/tools/usb/usbip/libsrc/vhci_driver.c +++ b/tools/usb/usbip/libsrc/vhci_driver.c @@ -55,12 +55,12 @@ static int parse_status(const char *valu while (*c != '\0') { int port, status, speed, devid; - unsigned long socket; + int sockfd; char lbusid[SYSFS_BUS_ID_SIZE]; - ret = sscanf(c, "%d %d %d %x %lx %31s\n", + ret = sscanf(c, "%d %d %d %x %u %31s\n", &port, &status, &speed, - &devid, &socket, lbusid); + &devid, &sockfd, lbusid); if (ret < 5) { dbg("sscanf failed: %d", ret); @@ -69,7 +69,7 @@ static int parse_status(const char *valu dbg("port %d status %d speed %d devid %x", port, status, speed, devid); - dbg("socket %lx lbusid %s", socket, lbusid); + dbg("sockfd %u lbusid %s", sockfd, lbusid); /* if a device is connected, look at it */