4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> 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@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/uwb/uwbd.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/drivers/uwb/uwbd.c +++ b/drivers/uwb/uwbd.c @@ -303,18 +303,22 @@ 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); }