This is a note to let you know that I've just added the patch titled
usbip: prevent vhci_hcd driver from leaking a socket pointer address
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 2f2d0088eb93db5c649d2a5e34a3800a8a935fc5 Mon Sep 17 00:00:00 2001
From: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Date: Thu, 7 Dec 2017 14:16:49 -0700
Subject: 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@xxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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, 21 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/usbip/usbip_common.h b/drivers/usb/usbip/usbip_common.h
index e5de35c8c505..473fb8a87289 100644
--- a/drivers/usb/usbip/usbip_common.h
+++ b/drivers/usb/usbip/usbip_common.h
@@ -256,6 +256,7 @@ 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 e78f7472cac4..091f76b7196d 100644
--- a/drivers/usb/usbip/vhci_sysfs.c
+++ b/drivers/usb/usbip/vhci_sysfs.c
@@ -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;
diff --git a/tools/usb/usbip/libsrc/vhci_driver.c b/tools/usb/usbip/libsrc/vhci_driver.c
index 627d1dfc332b..c9c81614a66a 100644
--- 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];
--
2.15.1