[PATCH 3.2 012/106] USB: core: replace %p with %pK

From: Ben Hutchings
Date: Sat Sep 09 2017 - 18:59:47 EST


3.2.93-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Vamsi Krishna Samavedam <vskrishn@xxxxxxxxxxxxxx>

commit 2f964780c03b73de269b08d12aff96a9618d13f3 upstream.

Format specifier %p can leak kernel addresses while not valuing the
kptr_restrict system settings. When kptr_restrict is set to (1), kernel
pointers printed using the %pK format specifier will be replaced with
Zeros. Debugging Note : &pK prints only Zeros as address. If you need
actual address information, write 0 to kptr_restrict.

echo 0 > /proc/sys/kernel/kptr_restrict

[Found by poking around in a random vendor kernel tree, it would be nice
if someone would actually send these types of patches upstream - gkh]

Signed-off-by: Vamsi Krishna Samavedam <vskrishn@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: drop changes in proc_reapurb*(), usbdev_do_ioctl(),
usb_submit_urb()]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -325,11 +325,11 @@ static void snoop_urb(struct usb_device

if (userurb) { /* Async */
if (when == SUBMIT)
- dev_info(&udev->dev, "userurb %p, ep%d %s-%s, "
+ dev_info(&udev->dev, "userurb %pK, ep%d %s-%s, "
"length %u\n",
userurb, ep, t, d, length);
else
- dev_info(&udev->dev, "userurb %p, ep%d %s-%s, "
+ dev_info(&udev->dev, "userurb %pK, ep%d %s-%s, "
"actual_length %u status %d\n",
userurb, ep, t, d, length,
timeout_or_status);
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1563,7 +1563,7 @@ int usb_hcd_unlink_urb (struct urb *urb,
if (retval == 0)
retval = -EINPROGRESS;
else if (retval != -EIDRM && retval != -EBUSY)
- dev_dbg(&udev->dev, "hcd_unlink_urb %p fail %d\n",
+ dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
urb, retval);
usb_put_dev(udev);
}
@@ -1645,7 +1645,7 @@ rescan:
/* kick hcd */
unlink1(hcd, urb, -ESHUTDOWN);
dev_dbg (hcd->self.controller,
- "shutdown urb %p ep%d%s%s\n",
+ "shutdown urb %pK ep%d%s%s\n",
urb, usb_endpoint_num(&ep->desc),
is_in ? "in" : "out",
({ char *s;