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patch "USB: core: Change %pK for __user pointers to %px" added to usb-linus

PATCH [email protected] 1 participant 1 message Nov 20, 2020

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This is a note to let you know that I've just added the patch titled

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

to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From f3bc432aa8a7a2bfe9ebb432502be5c5d979d7fe Mon Sep 17 00:00:00 2001
From: Alan Stern <[email protected]>
Date: Thu, 19 Nov 2020 12:02:28 -0500
Subject: 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 <[email protected]>
CC <[email protected]>
Signed-off-by Alan Stern <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/usb/core/devio.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)
drivers/usb/core/devio.c +7 -7
index e96a858a1218..533236366a03 100644
@@ -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;
Signature · 1 line
2.29.2