From 87f20f704cc66d3878c1a62f0a2ffe5a5e202274 Mon Sep 17 00:00:00 2001
From: Tom <tomut@yahoo.com>
Date: Wed, 30 Sep 2020 19:08:54 -0600
Subject: [PATCH] Kernel: Add checks for is_trivially_copyable to
 copy_to/from_user

If we're copying structures, we only ever want to copy trivially
copyable structures.
---
 Kernel/StdLib.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/Kernel/StdLib.h b/Kernel/StdLib.h
index fb64af7ab28..f900cb15718 100644
--- a/Kernel/StdLib.h
+++ b/Kernel/StdLib.h
@@ -61,48 +61,56 @@ inline u16 htons(u16 w) { return (w & 0xff) << 8 | ((w >> 8) & 0xff); }
 template<typename T>
 [[nodiscard]] inline bool copy_from_user(T* dest, const T* src)
 {
+    static_assert(is_trivially_copyable<T>());
     return copy_from_user(dest, src, sizeof(T));
 }
 
 template<typename T>
 [[nodiscard]] inline bool copy_to_user(T* dest, const T* src)
 {
+    static_assert(is_trivially_copyable<T>());
     return copy_to_user(dest, src, sizeof(T));
 }
 
 template<typename T>
 [[nodiscard]] inline bool copy_from_user(T* dest, Userspace<const T*> src)
 {
+    static_assert(is_trivially_copyable<T>());
     return copy_from_user(dest, src.unsafe_userspace_ptr(), sizeof(T));
 }
 
 template<typename T>
 [[nodiscard]] inline bool copy_from_user(T* dest, Userspace<T*> src)
 {
+    static_assert(is_trivially_copyable<T>());
     return copy_from_user(dest, src.unsafe_userspace_ptr(), sizeof(T));
 }
 
 template<typename T>
 [[nodiscard]] inline bool copy_to_user(Userspace<T*> dest, const T* src)
 {
+    static_assert(is_trivially_copyable<T>());
     return copy_to_user(dest.unsafe_userspace_ptr(), src, sizeof(T));
 }
 
 template<typename T>
 [[nodiscard]] inline bool copy_to_user(Userspace<T*> dest, const void* src, size_t size)
 {
+    static_assert(is_trivially_copyable<T>());
     return copy_to_user(dest.unsafe_userspace_ptr(), src, size);
 }
 
 template<typename T>
 [[nodiscard]] inline bool copy_from_user(void* dest, Userspace<const T*> src, size_t size)
 {
+    static_assert(is_trivially_copyable<T>());
     return copy_from_user(dest, src.unsafe_userspace_ptr(), size);
 }
 
 template<typename T>
 [[nodiscard]] inline bool copy_n_from_user(T* dest, const T* src, size_t count)
 {
+    static_assert(is_trivially_copyable<T>());
     Checked size = sizeof(T);
     size *= count;
     if (size.has_overflow())
@@ -113,6 +121,7 @@ template<typename T>
 template<typename T>
 [[nodiscard]] inline bool copy_n_to_user(T* dest, const T* src, size_t count)
 {
+    static_assert(is_trivially_copyable<T>());
     Checked size = sizeof(T);
     size *= count;
     if (size.has_overflow())
@@ -123,6 +132,7 @@ template<typename T>
 template<typename T>
 [[nodiscard]] inline bool copy_n_from_user(T* dest, Userspace<const T*> src, size_t count)
 {
+    static_assert(is_trivially_copyable<T>());
     Checked size = sizeof(T);
     size *= count;
     if (size.has_overflow())
@@ -133,6 +143,7 @@ template<typename T>
 template<typename T>
 [[nodiscard]] inline bool copy_n_to_user(Userspace<T*> dest, const T* src, size_t count)
 {
+    static_assert(is_trivially_copyable<T>());
     Checked size = sizeof(T);
     size *= count;
     if (size.has_overflow())