util: fix OOM in inspect color stack formatting

Signed-off-by: Ijtihed Kilani <ijtihedk@gmail.com>
PR-URL: #64022
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Aviv Keller <me@aviv.sh>

Author: Ijtihed

lib/internal/util/inspect.js

@@ -1876,9 +1876,15 @@ function markNodeModules(ctx, line) {
     tempLine += StringPrototypeSlice(line, lastPos, moduleStart);
 
     let moduleEnd = StringPrototypeIndexOf(line, separator, moduleStart);
-    if (line[moduleStart] === '@') {
+    if (moduleEnd === -1) {
+      // No trailing separator: the module name runs to the end of the line.
+      moduleEnd = line.length;
+    } else if (line[moduleStart] === '@') {
       // Namespaced modules have an extra slash: @namespace/package
       moduleEnd = StringPrototypeIndexOf(line, separator, moduleEnd + 1);
+      if (moduleEnd === -1) {
+        moduleEnd = line.length;
+      }
     }
 
     const nodeModule = StringPrototypeSlice(line, moduleStart, moduleEnd);

test/parallel/test-util-inspect.js

@@ -3418,6 +3418,21 @@ assert.strictEqual(
   );
 }
 
+{
+  // A node_modules segment that is the last path component (no trailing
+  // separator after the module name) must not send markNodeModules into an
+  // infinite loop that exhausts the heap.
+  // https://github.com/nodejs/node/issues/64011
+  const err = new Error('boom');
+  err.stack = 'Error: boom\n    at /app/node_modules/foo.js:1:1';
+  const out = util.inspect(err, { colors: true });
+  assert.strictEqual(
+    out,
+    'Error: boom\n' +
+      '    at /app/node_modules/\x1B[4mfoo.js:1:1\x1B[24m',
+  );
+}
+
 {
   // Cross platform checks.
   const err = new Error('foo');