usbip: prevent vhci_hcd driver from leaking a socket pointer address

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 <vuln@secunia.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h
index 3050fc9..33737b6 100644 (file)
--- a/drivers/usb/usbip/usbip_common.h
+++ b/drivers/usb/usbip/usbip_common.h
@@ -270,6 +270,7 @@ 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 1b9f60a..84df63e 100644 (file)
--- a/drivers/usb/usbip/vhci_sysfs.c
+++ b/drivers/usb/usbip/vhci_sysfs.c
@@ -31,15 +31,20 @@
 
 /*
  * 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)
 {
@@ -53,8 +58,8 @@ 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 {
@@ -174,7 +179,8 @@ 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;
@@ -380,6 +386,7 @@ 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 8a1cd16..d1fc0f9 100644 (file)
--- 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];