commit 2f2d0088eb93 ("usbip: prevent vhci_hcd driver from leaking a socket pointer address")

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 vuln@secunia.com Signed-off-by: Shuah Khan shuahkh@osg.samsung.com --- 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(-)

diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h index 86b08475c254..f875ccaa55f9 100644 --- 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; diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c index 211f43f67ea2..84c21c4ccf46 100644 --- 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 *dev, struct device_attribute *attr,

/* * 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 *dev, struct device_attribute *attr, 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 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 ad9204773533..1274f326242c 100644 --- 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 *value)

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 *value)

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 */