Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752582AbdLGVRW (ORCPT ); Thu, 7 Dec 2017 16:17:22 -0500 Received: from osg.samsung.com ([64.30.133.232]:63249 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752365AbdLGVRS (ORCPT ); Thu, 7 Dec 2017 16:17:18 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Shuah Khan To: shuah@kernel.org, valentina.manea.m@gmail.com, gregkh@linuxfoundation.org Cc: Shuah Khan , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] usbip: prevent vhci_hcd driver from leaking a socket pointer address Date: Thu, 7 Dec 2017 14:16:49 -0700 Message-Id: <96d723665e9feda55f38a2d4d5cd23b4201cb70d.1512672005.git.shuahkh@osg.samsung.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4657 Lines: 125 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. Signed-off-by: Shuah Khan --- 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, 21 insertions(+), 13 deletions(-) diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h index e5de35c8c505..473fb8a87289 100644 --- a/drivers/usb/usbip/usbip_common.h +++ b/drivers/usb/usbip/usbip_common.h @@ -256,6 +256,7 @@ struct usbip_device { /* lock for status */ spinlock_t lock; + int sockfd; struct socket *tcp_socket; struct task_struct *tcp_rx; diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c index e78f7472cac4..091f76b7196d 100644 --- a/drivers/usb/usbip/vhci_sysfs.c +++ b/drivers/usb/usbip/vhci_sysfs.c @@ -17,15 +17,20 @@ /* * output example: - * hub port sta spd dev socket local_busid - * hs 0000 004 000 00000000 c5a7bb80 1-2.3 + * hub port sta spd dev sockfd local_busid + * hs 0000 004 000 00000000 3 1-2.3 * ................................................ - * ss 0008 004 000 00000000 d8cee980 2-3.4 + * ss 0008 004 000 00000000 4 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. + * */ static void port_show_vhci(char **out, int hub, int port, struct vhci_device *vdev) { @@ -39,8 +44,8 @@ static void port_show_vhci(char **out, int hub, int port, struct vhci_device *vd if (vdev->ud.status == VDEV_ST_USED) { *out += sprintf(*out, "%03u %08x ", vdev->speed, vdev->devid); - *out += sprintf(*out, "%16p %s", - vdev->ud.tcp_socket, + *out += sprintf(*out, "%u %s", + vdev->ud.sockfd, dev_name(&vdev->udev->dev)); } else { @@ -160,7 +165,8 @@ static ssize_t nports_show(struct device *dev, struct device_attribute *attr, char *s = out; /* - * Half the ports are for SPEED_HIGH and half for SPEED_SUPER, thus the * 2. + * Half the ports are for SPEED_HIGH and half for SPEED_SUPER, + * thus the * 2. */ out += sprintf(out, "%d\n", VHCI_PORTS * vhci_num_controllers); return out - s; @@ -366,6 +372,7 @@ static ssize_t store_attach(struct device *dev, struct device_attribute *attr, vdev->devid = devid; vdev->speed = speed; + vdev->ud.sockfd = sockfd; vdev->ud.tcp_socket = socket; vdev->ud.status = VDEV_ST_NOTASSIGNED; diff --git a/tools/usb/usbip/libsrc/vhci_driver.c b/tools/usb/usbip/libsrc/vhci_driver.c index 8a1cd1616de4..d1fc0f9f00fb 100644 --- a/tools/usb/usbip/libsrc/vhci_driver.c +++ b/tools/usb/usbip/libsrc/vhci_driver.c @@ -50,14 +50,14 @@ static int parse_status(const char *value) while (*c != '\0') { int port, status, speed, devid; - unsigned long socket; + int sockfd; char lbusid[SYSFS_BUS_ID_SIZE]; struct usbip_imported_device *idev; char hub[3]; - ret = sscanf(c, "%2s %d %d %d %x %lx %31s\n", + ret = sscanf(c, "%2s %d %d %d %x %u %31s\n", hub, &port, &status, &speed, - &devid, &socket, lbusid); + &devid, &sockfd, lbusid); if (ret < 5) { dbg("sscanf failed: %d", ret); @@ -66,7 +66,7 @@ static int parse_status(const char *value) dbg("hub %s port %d status %d speed %d devid %x", hub, 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 */ idev = &vhci_driver->idev[port]; -- 2.14.1