[34-longterm 077/209] usb: core: fix information leak to userland

[Paul Gortmaker]

From: Vasiliy Kulikov <segooon@xxxxxxxxx>

  =====================================================================
  | This is a commit scheduled for the next v2.6.34 longterm release. |
  | If you see a problem with using this for longterm, please comment.|
  =====================================================================

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@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 drivers/usb/core/devio.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 3466fdc..6088192 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -966,10 +966,11 @@ 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;
-- 
1.7.4.4

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