[PATCH] usb: core: fix information leak to userland

From: Vasiliy Kulikov
Date: Sat Nov 06 2010 - 10:42:04 EST


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>
---
Compile tested.

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 f1aaff6..045bb4b 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -965,10 +965,11 @@ 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;
--
1.7.0.4

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