From bf43d94a2f0fc761158b0049e97fb69d8d273c8c Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Thu, 5 Sep 2019 11:13:10 +0200
Subject: [PATCH] Kernel: Disable interrupts throughout ~Region()

We don't want an interrupt handler to access the VM data structures
while their internal consistency is broken.
---
 Kernel/VM/Region.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Kernel/VM/Region.cpp b/Kernel/VM/Region.cpp
index 31cbda862c..6e778e5197 100644
--- a/Kernel/VM/Region.cpp
+++ b/Kernel/VM/Region.cpp
@@ -39,6 +39,10 @@ Region::Region(const Range& range, NonnullRefPtr<VMObject> vmo, size_t offset_in
 
 Region::~Region()
 {
+    // Make sure we disable interrupts so we don't get interrupted between unmapping and unregistering.
+    // Unmapping the region will give the VM back to the RangeAllocator, so an interrupt handler would
+    // find the address<->region mappings in an invalid state there.
+    InterruptDisabler disabler;
     if (m_page_directory) {
         MM.unmap_region(*this);
         ASSERT(!m_page_directory);