dns: coerce -0 to +0 in lookup and resolver inputs

panva · aduh95 · commit 0cf8342ae2d5 · 2026-06-18T10:09:48.000+02:00
Signed-off-by: Filip Skokan <panva.ip@gmail.com> PR-URL: #63556 Reviewed-By: Jordan Harband <ljharb@gmail.com> Reviewed-By: Chemi Atlow <chemi@atlow.co.il>
diff --git a/lib/dns.js b/lib/dns.js
@@ -157,7 +157,8 @@ function lookup(hostname, options, callback) {
     validateFunction(callback, 'callback');
 
     validateOneOf(options, 'family', validFamilies);
-    family = options;
+    // Coerce -0 to +0.
+    family = options + 0;
   } else if (options !== undefined && typeof options !== 'object') {
     validateFunction(arguments.length === 2 ? options : callback, 'callback');
     throw new ERR_INVALID_ARG_TYPE('options', ['integer', 'object'], options);
@@ -179,7 +180,8 @@ function lookup(hostname, options, callback) {
           break;
         default:
           validateOneOf(options.family, 'options.family', validFamilies);
-          family = options.family;
+          // Coerce -0 to +0.
+          family = options.family + 0;
           break;
       }
     }
@@ -274,7 +276,8 @@ function lookupService(address, port, callback) {
 
   validateFunction(callback, 'callback');
 
-  port = +port;
+  // Coerce -0 to +0.
+  port = +port + 0;
 
   const req = new GetNameInfoReqWrap();
   req.callback = callback;
diff --git a/lib/internal/dns/promises.js b/lib/internal/dns/promises.js
@@ -206,7 +206,8 @@ function lookup(hostname, options) {
 
   if (typeof options === 'number') {
     validateOneOf(options, 'family', validFamilies);
-    family = options;
+    // Coerce -0 to +0.
+    family = options + 0;
   } else if (options !== undefined && typeof options !== 'object') {
     throw new ERR_INVALID_ARG_TYPE('options', ['integer', 'object'], options);
   } else {
@@ -217,7 +218,8 @@ function lookup(hostname, options) {
     }
     if (options?.family != null) {
       validateOneOf(options.family, 'options.family', validFamilies);
-      family = options.family;
+      // Coerce -0 to +0.
+      family = options.family + 0;
     }
     if (options?.all != null) {
       validateBoolean(options.all, 'options.all');
diff --git a/lib/internal/dns/utils.js b/lib/internal/dns/utils.js
@@ -45,14 +45,18 @@ const {
 } = require('internal/v8/startup_snapshot');
 
 function validateTimeout(options) {
-  const { timeout = -1 } = { ...options };
+  let { timeout = -1 } = { ...options };
   validateInt32(timeout, 'options.timeout', -1);
+  // Coerce -0 to +0.
+  timeout += 0;
   return timeout;
 }
 
 function validateMaxTimeout(options) {
-  const { maxTimeout = 0 } = { ...options };
+  let { maxTimeout = 0 } = { ...options };
   validateUint32(maxTimeout, 'options.maxTimeout');
+  // Coerce -0 to +0.
+  maxTimeout += 0;
   return maxTimeout;
 }
 
diff --git a/test/parallel/test-dns-negative-zero.js b/test/parallel/test-dns-negative-zero.js
@@ -0,0 +1,14 @@
+'use strict';
+
+const common = require('../common');
+
+const dns = require('dns');
+
+dns.lookup('localhost', -0, common.mustCall());
+dns.lookup('localhost', { family: -0 }, common.mustCall());
+dns.lookupService('127.0.0.1', -0, common.mustCall());
+
+new dns.Resolver({ timeout: -0 });
+new dns.Resolver({ maxTimeout: -0 });
+
+dns.promises.lookup('localhost', { family: -0 }).then(common.mustCall());
