usb: core: fix information leak to userland

commit 886ccd4520064408ce5876cfe00554ce52ecf4a7 upstream.

Structure usbdevfs_connectinfo is copied to userland with padding byted
after "slow" field uninitialized.  It leads to leaking of contents of
kernel stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 8657266..a3397c8 100644 (file)
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -883,10 +883,11 @@ static int proc_getdriver(struct dev_state *ps, void __user *arg)
 
 static int proc_connectinfo(struct dev_state *ps, void __user *arg)
 {
-       struct usbdevfs_connectinfo ci;
+       struct usbdevfs_connectinfo ci = {
+               .devnum = ps->dev->devnum,
+               .slow = ps->dev->speed == USB_SPEED_LOW
+       };
 
-       ci.devnum = ps->dev->devnum;
-       ci.slow = ps->dev->speed == USB_SPEED_LOW;
        if (copy_to_user(arg, &ci, sizeof(ci)))
                return -EFAULT;
        return 0;