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Co-authored-by: Simon Friis Vindum <[email protected]>

Author: geoffw0

rust/ql/lib/codeql/rust/security/AccessAfterLifetimeExtensions.qll

@@ -81,13 +81,13 @@ module AccessAfterLifetime {
   }
 
   /**
-   * Holds if block `a` contains block `b`, in the sense that a variable in
-   * `a` may be on the stack during execution of `b`. This is interprocedural,
+   * Holds if block `a` contains block `b`, in the sense that a stack allocated variable in
+   * `a` may still be on the stack during execution of `b`. This is interprocedural,
    * but is an overapproximation that doesn't accurately track call contexts
    * (for example if `f` and `g` both call `b`, then then depending on the
    * caller a variable in `f` or `g` may or may-not be on the stack during `b`).
    */
-  private predicate maybeOnStack(BlockExpr a, BlockExpr b) {
+  private predicate blockStackEnclosing(BlockExpr a, BlockExpr b) {
     // `b` is a child of `a`
     a = b.getEnclosingBlock*()
     or

rust/ql/src/queries/security/CWE-825/AccessAfterLifetimeBad.rs

@@ -2,7 +2,7 @@
 fn get_pointer() -> *const i64 {
 	let val = 123;
 
-	return &val;
+	&val
 } // lifetime of `val` ends here, the pointer becomes dangling
 
 fn example() {

rust/ql/src/queries/security/CWE-825/AccessAfterLifetimeGood.rs

@@ -2,7 +2,7 @@
 fn get_box() -> Box<i64> {
 	let val = 123;
 
-	return Box::new(val); // copies `val` onto the heap, where it remains for the lifetime of the `Box`.
+	Box::new(val) // copies `val` onto the heap, where it remains for the lifetime of the `Box`.
 }
 
 fn example() {