Patch "watchdog: rc32434_wdt: fix ioctl error handling" has been added to the 4.4-stable tree

Patch "watchdog: rc32434_wdt: fix ioctl error handling" has been added to the 4.4-stable tree

[gregkh]

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

    watchdog: rc32434_wdt: fix ioctl error handling

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     watchdog-rc32434_wdt-fix-ioctl-error-handling.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 10e7ac22cdd4d211cef99afcb9371b70cb175be6 Mon Sep 17 00:00:00 2001
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Sun, 28 Feb 2016 17:44:09 +0200
Subject: watchdog: rc32434_wdt: fix ioctl error handling

From: Michael S. Tsirkin <mst@redhat.com>

commit 10e7ac22cdd4d211cef99afcb9371b70cb175be6 upstream.

Calling return copy_to_user(...) in an ioctl will not do the right thing
if there's a pagefault: copy_to_user returns the number of bytes not
copied in this case.

Fix up watchdog/rc32434_wdt to do
	return copy_to_user(...)) ?  -EFAULT : 0;

instead.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/watchdog/rc32434_wdt.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/watchdog/rc32434_wdt.c
+++ b/drivers/watchdog/rc32434_wdt.c
@@ -237,7 +237,7 @@ static long rc32434_wdt_ioctl(struct fil
 			return -EINVAL;
 		/* Fall through */
 	case WDIOC_GETTIMEOUT:
-		return copy_to_user(argp, &timeout, sizeof(int));
+		return copy_to_user(argp, &timeout, sizeof(int)) ? -EFAULT : 0;
 	default:
 		return -ENOTTY;
 	}


Patches currently in stable-queue which might be from mst@redhat.com are

queue-4.4/watchdog-rc32434_wdt-fix-ioctl-error-handling.patch