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usbip: prevent vhci_hcd driver from leaking a socket pointer address

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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>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Shuah Khan 2017-12-07 14:16:49 -07:00 committed by Greg Kroah-Hartman
parent c6688ef9f2
commit 2f2d0088eb
3 changed files with 21 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/usb/usbip/usbip_common.h
View File

@ -256,6 +256,7 @@ struct usbip_device {
/* lock for status */
spinlock_t lock;
int sockfd;
struct socket *tcp_socket;
struct task_struct *tcp_rx;

25
drivers/usb/usbip/vhci_sysfs.c
View File

@ -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;

8
tools/usb/usbip/libsrc/vhci_driver.c
View File

@ -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];