2 files changed, 15 insertions, 3 deletions

diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index b3c7fd554250..6144bab8fd8e 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -232,15 +232,19 @@ static int pid_ns_ctl_handler(struct ctl_table *table, int write,
          */
 
         tmp.data = &current->nsproxy->pid_ns->last_pid;
-        return proc_dointvec(&tmp, write, buffer, lenp, ppos);
+        return proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
 }
 
+extern int pid_max;
+static int zero = 0;
 static struct ctl_table pid_ns_ctl_table[] = {
         {
                 .procname = "ns_last_pid",
                 .maxlen = sizeof(int),
                 .mode = 0666, /* permissions are checked in the handler */
                 .proc_handler = pid_ns_ctl_handler,
+                .extra1 = &zero,
+                .extra2 = &pid_max,
         },
         { }
 };
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1e1373bcb3e3..b80065a2450a 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -1349,8 +1349,16 @@ static void busy_worker_rebind_fn(struct work_struct *work)
         struct worker *worker = container_of(work, struct worker, rebind_work);
         struct global_cwq *gcwq = worker->pool->gcwq;
 
-        if (worker_maybe_bind_and_lock(worker))
-                worker_clr_flags(worker, WORKER_REBIND);
+        worker_maybe_bind_and_lock(worker);
+
+        /*
+         * %WORKER_REBIND must be cleared even if the above binding failed;
+         * otherwise, we may confuse the next CPU_UP cycle or oops / get
+         * stuck by calling idle_worker_rebind() prematurely.  If CPU went
+         * down again inbetween, %WORKER_UNBOUND would be set, so clearing
+         * %WORKER_REBIND is always safe.
+         */
+        worker_clr_flags(worker, WORKER_REBIND);
 
         spin_unlock_irq(&gcwq->lock);
 }