1 files changed, 7 insertions, 1 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 91b789dd6e72..534fec266a33 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -90,6 +90,11 @@ static bool sig_task_ignored(struct task_struct *t, int sig, bool force)
             handler == SIG_DFL && !(force && sig_kernel_only(sig)))
                 return true;
 
+        /* Only allow kernel generated signals to this kthread */
+        if (unlikely((t->flags & PF_KTHREAD) &&
+                     (handler == SIG_KTHREAD_KERNEL) && !force))
+                return true;
+
         return sig_handler_ignored(handler, sig);
 }
 
@@ -349,7 +354,7 @@ void task_clear_jobctl_pending(struct task_struct *task, unsigned long mask)
  * @task has %JOBCTL_STOP_PENDING set and is participating in a group stop.
  * Group stop states are cleared and the group stop count is consumed if
  * %JOBCTL_STOP_CONSUME was set.  If the consumption completes the group
- * stop, the appropriate %SIGNAL_* flags are set.
+ * stop, the appropriate `SIGNAL_*` flags are set.
  *
  * CONTEXT:
  * Must be called with @task->sighand->siglock held.
@@ -1885,6 +1890,7 @@ static void do_notify_pidfd(struct task_struct *task)
 {
         struct pid *pid;
 
+        WARN_ON(task->exit_state == 0);
         pid = task_pid(task);
         wake_up_all(&pid->wait_pidfd);
 }