From e37e4a7980376b6982e11bba59316534f9cf7dbb Mon Sep 17 00:00:00 2001
From: Idan Horowitz <idan.horowitz@gmail.com>
Date: Mon, 14 Feb 2022 01:46:34 +0200
Subject: [PATCH] Kernel: Make Inode::set_shared_vmobject() OOM-fallible

Allocating a WeakPtr can fail, so this let's us properly propagate said
failure.
---
 Kernel/FileSystem/Inode.cpp           | 5 +++--
 Kernel/FileSystem/Inode.h             | 2 +-
 Kernel/Memory/SharedInodeVMObject.cpp | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/Kernel/FileSystem/Inode.cpp b/Kernel/FileSystem/Inode.cpp
index a8822a1e23..bfe2e4210d 100644
--- a/Kernel/FileSystem/Inode.cpp
+++ b/Kernel/FileSystem/Inode.cpp
@@ -130,10 +130,11 @@ ErrorOr<void> Inode::decrement_link_count()
     return ENOTIMPL;
 }
 
-void Inode::set_shared_vmobject(Memory::SharedInodeVMObject& vmobject)
+ErrorOr<void> Inode::set_shared_vmobject(Memory::SharedInodeVMObject& vmobject)
 {
     MutexLocker locker(m_inode_lock);
-    m_shared_vmobject = vmobject;
+    m_shared_vmobject = TRY(vmobject.try_make_weak_ptr<Memory::SharedInodeVMObject>());
+    return {};
 }
 
 RefPtr<LocalSocket> Inode::bound_socket() const
diff --git a/Kernel/FileSystem/Inode.h b/Kernel/FileSystem/Inode.h
index 7351e892e2..2056da0bf4 100644
--- a/Kernel/FileSystem/Inode.h
+++ b/Kernel/FileSystem/Inode.h
@@ -82,7 +82,7 @@ public:
 
     void will_be_destroyed();
 
-    void set_shared_vmobject(Memory::SharedInodeVMObject&);
+    ErrorOr<void> set_shared_vmobject(Memory::SharedInodeVMObject&);
     RefPtr<Memory::SharedInodeVMObject> shared_vmobject() const;
 
     static void sync_all();
diff --git a/Kernel/Memory/SharedInodeVMObject.cpp b/Kernel/Memory/SharedInodeVMObject.cpp
index fdda7d7860..3c20012718 100644
--- a/Kernel/Memory/SharedInodeVMObject.cpp
+++ b/Kernel/Memory/SharedInodeVMObject.cpp
@@ -18,7 +18,7 @@ ErrorOr<NonnullRefPtr<SharedInodeVMObject>> SharedInodeVMObject::try_create_with
     auto new_physical_pages = TRY(VMObject::try_create_physical_pages(size));
     auto dirty_pages = TRY(Bitmap::try_create(new_physical_pages.size(), false));
     auto vmobject = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) SharedInodeVMObject(inode, move(new_physical_pages), move(dirty_pages))));
-    vmobject->inode().set_shared_vmobject(*vmobject);
+    TRY(vmobject->inode().set_shared_vmobject(*vmobject));
     return vmobject;
 }