From 32d7f77780ec9f7735e729ca1ead8bcc07597163 Mon Sep 17 00:00:00 2001
From: Martin Hughes <martin-hughes@users.noreply.github.com>
Date: Wed, 24 Jun 2026 15:57:50 +0100
Subject: [PATCH] Keep a copy of block stream instead of raw pointer

This mitigates the possibility of the pointed-to code stream being
dropped, which would result in a use-after-free.

Fixes #300.

The use of a Vec isn't the most memory or CPU efficient. I tried using
borrows but it was leading to a horrible mess of lifetime specifiers
and there were still a few areas of code I couldn't figure out how to
make compile...
---
 src/aml/mod.rs          | 17 +++++------------
 tests/uacpi_examples.rs |  1 -
 2 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/src/aml/mod.rs b/src/aml/mod.rs
index bdd0dfc3..cb3af956 100644
--- a/src/aml/mod.rs
+++ b/src/aml/mod.rs
@@ -2855,13 +2855,6 @@ where
 
 /// A `MethodContext` represents a piece of running AML code - either a real method, or the
 /// top-level of an AML table.
-///
-/// ### Safety
-/// `MethodContext` does not keep the lifetime of the underlying AML stream, which for tables is
-/// borrowed from the underlying physical mapping. This is because the interpreter needs to
-/// preempt method contexts that execute other methods, and these contexts may have disparate
-/// lifetimes. This is made safe in the case of methods by the context holding a reference to the
-/// method object, but must be handled manually for AML tables.
 struct MethodContext {
     current_block: Block,
     block_stack: Vec<Block>,
@@ -2874,14 +2867,14 @@ struct MethodContext {
 }
 
 struct Block {
-    stream: *const [u8],
+    stream: Vec<u8>,
     pc: usize,
     kind: BlockKind,
 }
 
 impl Block {
     fn stream(&self) -> &[u8] {
-        unsafe { &*self.stream }
+        &self.stream
     }
 }
 
@@ -3009,7 +3002,7 @@ impl OpInFlight {
 
 impl MethodContext {
     unsafe fn new_from_table(stream: &[u8]) -> MethodContext {
-        let block = Block { stream: stream as *const [u8], pc: 0, kind: BlockKind::Table };
+        let block = Block { stream: Vec::from(stream), pc: 0, kind: BlockKind::Table };
         MethodContext {
             current_block: block,
             block_stack: Vec::new(),
@@ -3031,7 +3024,7 @@ impl MethodContext {
                 return Err(AmlError::MethodArgCountIncorrect);
             }
             let block = Block {
-                stream: code as &[u8] as *const [u8],
+                stream: code.clone(),
                 pc: 0,
                 kind: BlockKind::Method { method_scope: scope.clone() },
             };
@@ -3079,7 +3072,7 @@ impl MethodContext {
 
     fn start_new_block(&mut self, kind: BlockKind, length: usize) {
         let block = Block {
-            stream: &self.current_block.stream()[..(self.current_block.pc + length)] as *const [u8],
+            stream: self.current_block.stream()[..(self.current_block.pc + length)].into(),
             pc: self.current_block.pc,
             kind,
         };
diff --git a/tests/uacpi_examples.rs b/tests/uacpi_examples.rs
index 4c1aa82d..128fe30f 100644
--- a/tests/uacpi_examples.rs
+++ b/tests/uacpi_examples.rs
@@ -181,7 +181,6 @@ DefinitionBlock("", "DSDT", 1, "RSACPI", "UACPI", 1) {
 }
 
 #[test]
-#[ignore] // See issue #300
 fn copy_object_to_self() {
     const ASL: &str = r#"
 DefinitionBlock("", "DSDT", 1, "RSACPI", "UACPI", 1) {