diff --git a/Kernel/Memory/AnonymousVMObject.cpp b/Kernel/Memory/AnonymousVMObject.cpp
index a882671f6e..8cd4915432 100644
--- a/Kernel/Memory/AnonymousVMObject.cpp
+++ b/Kernel/Memory/AnonymousVMObject.cpp
@@ -346,9 +346,10 @@ PageFaultResponse AnonymousVMObject::handle_cow_fault(size_t page_index, Virtual
         }
     }
 
-    u8* dest_ptr = MM.quickmap_page(*page);
     dbgln_if(PAGE_FAULT_DEBUG, "      >> COW {} <- {}", page->paddr(), page_slot->paddr());
     {
+        SpinlockLocker mm_locker(s_mm_lock);
+        u8* dest_ptr = MM.quickmap_page(*page);
         SmapDisabler disabler;
         void* fault_at;
         if (!safe_memcpy(dest_ptr, vaddr.as_ptr(), PAGE_SIZE, fault_at)) {
@@ -361,9 +362,9 @@ PageFaultResponse AnonymousVMObject::handle_cow_fault(size_t page_index, Virtual
             else
                 VERIFY_NOT_REACHED();
         }
+        MM.unquickmap_page();
     }
     page_slot = move(page);
-    MM.unquickmap_page();
     set_should_cow(page_index, false);
     return PageFaultResponse::Continue;
 }
diff --git a/Kernel/Memory/MemoryManager.cpp b/Kernel/Memory/MemoryManager.cpp
index 237e60e6d7..324f9cb083 100644
--- a/Kernel/Memory/MemoryManager.cpp
+++ b/Kernel/Memory/MemoryManager.cpp
@@ -1004,9 +1004,9 @@ PageTableEntry* MemoryManager::quickmap_pt(PhysicalAddress pt_paddr)
 u8* MemoryManager::quickmap_page(PhysicalAddress const& physical_address)
 {
     VERIFY_INTERRUPTS_DISABLED();
+    VERIFY(s_mm_lock.own_lock());
     auto& mm_data = get_data();
     mm_data.m_quickmap_prev_flags = mm_data.m_quickmap_in_use.lock();
-    SpinlockLocker lock(s_mm_lock);
 
     VirtualAddress vaddr(KERNEL_QUICKMAP_PER_CPU_BASE + Processor::current_id() * PAGE_SIZE);
     u32 pte_idx = (vaddr.get() - KERNEL_PT1024_BASE) / PAGE_SIZE;
@@ -1025,7 +1025,7 @@ u8* MemoryManager::quickmap_page(PhysicalAddress const& physical_address)
 void MemoryManager::unquickmap_page()
 {
     VERIFY_INTERRUPTS_DISABLED();
-    SpinlockLocker lock(s_mm_lock);
+    VERIFY(s_mm_lock.own_lock());
     auto& mm_data = get_data();
     VERIFY(mm_data.m_quickmap_in_use.is_locked());
     VirtualAddress vaddr(KERNEL_QUICKMAP_PER_CPU_BASE + Processor::current_id() * PAGE_SIZE);
diff --git a/Kernel/Memory/Region.cpp b/Kernel/Memory/Region.cpp
index ad55d520df..c232e1bb7d 100644
--- a/Kernel/Memory/Region.cpp
+++ b/Kernel/Memory/Region.cpp
@@ -451,9 +451,12 @@ PageFaultResponse Region::handle_inode_fault(size_t page_index_in_region)
         return PageFaultResponse::OutOfMemory;
     }
 
-    u8* dest_ptr = MM.quickmap_page(*vmobject_physical_page_entry);
-    memcpy(dest_ptr, page_buffer, PAGE_SIZE);
-    MM.unquickmap_page();
+    {
+        SpinlockLocker mm_locker(s_mm_lock);
+        u8* dest_ptr = MM.quickmap_page(*vmobject_physical_page_entry);
+        memcpy(dest_ptr, page_buffer, PAGE_SIZE);
+        MM.unquickmap_page();
+    }
 
     remap_vmobject_page(page_index_in_vmobject);
     return PageFaultResponse::Continue;