Update RSPEC

rules/S7453/rust/metadata.json

@@ -1,12 +1,13 @@
 {
-  "title": "FIXME",
-  "type": "CODE_SMELL",
+  "title": "Functions should not return mutable references from immutable parameters",
+  "type": "BUG",
   "status": "ready",
   "remediation": {
     "func": "Constant\/Issue",
     "constantCost": "5min"
   },
   "tags": [
+    "clippy"
   ],
   "defaultSeverity": "Major",
   "ruleSpecification": "RSPEC-7453",
@@ -16,10 +17,8 @@
   "quickfix": "unknown",
   "code": {
     "impacts": {
-      "MAINTAINABILITY": "HIGH",
-      "RELIABILITY": "MEDIUM",
-      "SECURITY": "LOW"
+      "RELIABILITY": "MEDIUM"
     },
-    "attribute": "CONVENTIONAL"
+    "attribute": "LOGICAL"
   }
 }

rules/S7453/rust/rule.adoc

@@ -1,16 +1,6 @@
-FIXME: add a description
-
-// If you want to factorize the description uncomment the following line and create the file.
-//include::../description.adoc[]
-
 == Why is this an issue?
 
-FIXME: remove the unused optional headers (that are commented out)
-
-//=== What is the potential impact?
-
-== How to fix it
-//== How to fix it in FRAMEWORK NAME
+Creating a mutable reference from an immutable one is unsound because it can lead to multiple live mutable references to the same object, breaking Rust's guarantees of memory safety. Such patterns are particularly dangerous if unsafe code is present as it can lead to undefined behavior.
 
 === Code examples
 
@@ -18,27 +8,25 @@ FIXME: remove the unused optional headers (that are commented out)
 
 [source,rust,diff-id=1,diff-type=noncompliant]
 ----
-FIXME
+fn foo(x: &Foo) -> &mut Bar { 
+    unsafe {
+        // Noncompliant: Converting immutable reference to mutable.
+        &mut *(x as *const Foo as *mut Foo).bar 
+    }
+}
 ----
 
 ==== Compliant solution
 
 [source,rust,diff-id=1,diff-type=compliant]
 ----
-FIXME
+fn foo(x: &mut Foo) -> &mut Bar { 
+    // Compliant: Taking a mutable reference and returning a mutable reference.
+    &mut x.bar 
+}
 ----
 
-//=== How does this work?
+== Resources
+=== Documentation
 
-//=== Pitfalls
-
-//=== Going the extra mile
-
-
-//== Resources
-//=== Documentation
-//=== Articles & blog posts
-//=== Conference presentations
-//=== Standards
-//=== External coding guidelines
-//=== Benchmarks
+* Clippy Lints - https://rust-lang.github.io/rust-clippy/master/index.html#mut_from_ref