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usbip: prevent vhci_hcd driver from leaking a socket pointer address

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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>
This commit is contained in:
Shuah Khan 2017-12-07 14:16:49 -07:00 committed by Greg Kroah-Hartman
parent 8bb0c6a1b3
commit 28f467e0bd
3 changed files with 20 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

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

@ -261,6 +261,7 @@ 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

@ -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;

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

@ -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 */