From 4a293e8a214e9ccc9a1b72a775f5ad23b12e38e3 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 27 Feb 2020 11:03:21 +0100
Subject: [PATCH] Kernel: Ignore signals sent to threadless (zombie) processes

If a process doesn't have any threads left, it's in a zombie state and
we can't meaningfully send signals to it. So just ignore them.

Fixes #1313.
---
 Kernel/Process.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index 41f044a223..93085f6c9d 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -3719,6 +3719,8 @@ void Process::terminate_due_to_signal(u8 signal)
 void Process::send_signal(u8 signal, Process* sender)
 {
     InterruptDisabler disabler;
+    if (!m_thread_count)
+        return;
     auto* thread = Thread::from_tid(m_pid);
     if (!thread)
         thread = &any_thread();