From: Alan Stern <stern@rowland.harvard.edu>
Date: Thu, 19 Nov 2020 17:02:28 +0000 (-0500)
Subject: USB: core: Change %pK for __user pointers to %px
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f3bc432aa8a7a2bfe9ebb432502be5c5d979d7fe;p=linux.git

USB: core: Change %pK for __user pointers to %px

Commit 2f964780c03b ("USB: core: replace %p with %pK") used the %pK
format specifier for a bunch of __user pointers.  But as the 'K' in
the specifier indicates, it is meant for kernel pointers.  The reason
for the %pK specifier is to avoid leaks of kernel addresses, but when
the pointer is to an address in userspace the security implications
are minimal.  In particular, no kernel information is leaked.

This patch changes the __user %pK specifiers (used in a bunch of
debugging output lines) to %px, which will always print the actual
address with no mangling.  (Notably, there is no printk format
specifier particularly intended for __user pointers.)

Fixes: 2f964780c03b ("USB: core: replace %p with %pK")
CC: Vamsi Krishna Samavedam <vskrishn@codeaurora.org>
CC: <stable@vger.kernel.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20201119170228.GB576844@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index e96a858a12185..533236366a03b 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -482,11 +482,11 @@ static void snoop_urb(struct usb_device *udev,
 
 	if (userurb) {		/* Async */
 		if (when == SUBMIT)
-			dev_info(&udev->dev, "userurb %pK, ep%d %s-%s, "
+			dev_info(&udev->dev, "userurb %px, ep%d %s-%s, "
 					"length %u\n",
 					userurb, ep, t, d, length);
 		else
-			dev_info(&udev->dev, "userurb %pK, ep%d %s-%s, "
+			dev_info(&udev->dev, "userurb %px, ep%d %s-%s, "
 					"actual_length %u status %d\n",
 					userurb, ep, t, d, length,
 					timeout_or_status);
@@ -1997,7 +1997,7 @@ static int proc_reapurb(struct usb_dev_state *ps, void __user *arg)
 	if (as) {
 		int retval;
 
-		snoop(&ps->dev->dev, "reap %pK\n", as->userurb);
+		snoop(&ps->dev->dev, "reap %px\n", as->userurb);
 		retval = processcompl(as, (void __user * __user *)arg);
 		free_async(as);
 		return retval;
@@ -2014,7 +2014,7 @@ static int proc_reapurbnonblock(struct usb_dev_state *ps, void __user *arg)
 
 	as = async_getcompleted(ps);
 	if (as) {
-		snoop(&ps->dev->dev, "reap %pK\n", as->userurb);
+		snoop(&ps->dev->dev, "reap %px\n", as->userurb);
 		retval = processcompl(as, (void __user * __user *)arg);
 		free_async(as);
 	} else {
@@ -2142,7 +2142,7 @@ static int proc_reapurb_compat(struct usb_dev_state *ps, void __user *arg)
 	if (as) {
 		int retval;
 
-		snoop(&ps->dev->dev, "reap %pK\n", as->userurb);
+		snoop(&ps->dev->dev, "reap %px\n", as->userurb);
 		retval = processcompl_compat(as, (void __user * __user *)arg);
 		free_async(as);
 		return retval;
@@ -2159,7 +2159,7 @@ static int proc_reapurbnonblock_compat(struct usb_dev_state *ps, void __user *ar
 
 	as = async_getcompleted(ps);
 	if (as) {
-		snoop(&ps->dev->dev, "reap %pK\n", as->userurb);
+		snoop(&ps->dev->dev, "reap %px\n", as->userurb);
 		retval = processcompl_compat(as, (void __user * __user *)arg);
 		free_async(as);
 	} else {
@@ -2624,7 +2624,7 @@ static long usbdev_do_ioctl(struct file *file, unsigned int cmd,
 #endif
 
 	case USBDEVFS_DISCARDURB:
-		snoop(&dev->dev, "%s: DISCARDURB %pK\n", __func__, p);
+		snoop(&dev->dev, "%s: DISCARDURB %px\n", __func__, p);
 		ret = proc_unlinkurb(ps, p);
 		break;