3.16.54-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Shuah Khan <shua...@osg.samsung.com>

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 <v...@secunia.com>
Signed-off-by: Shuah Khan <shua...@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
[bwh: Backported to 3.16:
 - usbip port status does not include hub type
 - Adjust filenames, context, indentation]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/staging/usbip/usbip_common.h                 |  1 +
 drivers/staging/usbip/vhci_sysfs.c                   | 25 
++++++++++++++++---------
 drivers/staging/usbip/userspace/libsrc/vhci_driver.c |  8 ++++----
 3 files changed, 21 insertions(+), 13 deletions(-)

--- a/drivers/staging/usbip/usbip_common.h
+++ b/drivers/staging/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/staging/usbip/vhci_sysfs.c
+++ b/drivers/staging/usbip/vhci_sysfs.c
@@ -39,13 +39,18 @@ 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
+        * prt sta spd dev sockfd    local_busid
+        * 000 004 000 000 3         1-2.3
+        * 001 004 000 000 4         2-3.4
+        *
+        * 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.
         *
-        * 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.
         */
        out += sprintf(out,
                       "prt sta spd bus dev socket           local_busid\n");
@@ -59,7 +64,7 @@ static ssize_t status_show(struct device
                if (vdev->ud.status == VDEV_ST_USED) {
                        out += sprintf(out, "%03u %08x ",
                                       vdev->speed, vdev->devid);
-                       out += sprintf(out, "%16p ", vdev->ud.tcp_socket);
+                       out += sprintf(out, "%u", vdev->ud.sockfd);
                        out += sprintf(out, "%s", dev_name(&vdev->udev->dev));
 
                } else {
@@ -223,6 +228,7 @@ 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/drivers/staging/usbip/userspace/libsrc/vhci_driver.c
+++ b/drivers/staging/usbip/userspace/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 */

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