Patch "uwb: properly check kthread_run return value" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

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

    uwb: properly check kthread_run return value

to the 4.9-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:
     uwb-properly-check-kthread_run-return-value.patch
and it can be found in the queue-4.9 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 bbf26183b7a6236ba602f4d6a2f7cade35bba043 Mon Sep 17 00:00:00 2001
From: Andrey Konovalov <andreyknvl@google.com>
Date: Thu, 14 Sep 2017 14:30:55 +0200
Subject: uwb: properly check kthread_run return value

From: Andrey Konovalov <andreyknvl@google.com>

commit bbf26183b7a6236ba602f4d6a2f7cade35bba043 upstream.

uwbd_start() calls kthread_run() and checks that the return value is
not NULL. But the return value is not NULL in case kthread_run() fails,
it takes the form of ERR_PTR(-EINTR).

Use IS_ERR() instead.

Also add a check to uwbd_stop().

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/uwb/uwbd.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/drivers/uwb/uwbd.c
+++ b/drivers/uwb/uwbd.c
@@ -302,18 +302,22 @@ static int uwbd(void *param)
 /** Start the UWB daemon */
 void uwbd_start(struct uwb_rc *rc)
 {
-	rc->uwbd.task = kthread_run(uwbd, rc, "uwbd");
-	if (rc->uwbd.task == NULL)
+	struct task_struct *task = kthread_run(uwbd, rc, "uwbd");
+	if (IS_ERR(task)) {
+		rc->uwbd.task = NULL;
 		printk(KERN_ERR "UWB: Cannot start management daemon; "
 		       "UWB won't work\n");
-	else
+	} else {
+		rc->uwbd.task = task;
 		rc->uwbd.pid = rc->uwbd.task->pid;
+	}
 }
 
 /* Stop the UWB daemon and free any unprocessed events */
 void uwbd_stop(struct uwb_rc *rc)
 {
-	kthread_stop(rc->uwbd.task);
+	if (rc->uwbd.task)
+		kthread_stop(rc->uwbd.task);
 	uwbd_flush(rc);
 }
 


Patches currently in stable-queue which might be from andreyknvl@google.com are

queue-4.9/usb-fix-out-of-bounds-in-usb_set_configuration.patch
queue-4.9/usb-uas-fix-bug-in-handling-of-alternate-settings.patch
queue-4.9/alsa-usb-audio-check-out-of-bounds-access-by-corrupted-buffer-descriptor.patch
queue-4.9/uwb-properly-check-kthread_run-return-value.patch
queue-4.9/usb-dummy-hcd-fix-infinite-loop-resubmission-bug.patch
queue-4.9/usb-core-harden-cdc_parse_cdc_header.patch
queue-4.9/usb-gadgetfs-fix-copy_to_user-while-holding-spinlock.patch
queue-4.9/uwb-ensure-that-endpoint-is-interrupt.patch
queue-4.9/usb-gadgetfs-fix-crash-caused-by-inadequate-synchronization.patch