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

panva · aduh95 · commit d4cfe2d8ac90 · 2026-07-30T13:51:29.000+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
@@ -158,7 +158,8 @@ 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);
@@ -180,7 +181,8 @@ 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;
 }
 }
@@ -280,7 +282,8 @@ 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
@@ -207,7 +207,8 @@ 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 {
@@ -218,7 +219,8 @@ 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());

-Original file line number
+Diff line change
 validateFunction(callback,'callback');
 validateOneOf(options,'family',validFamilies);
 -family=options;
 +// Coerce -0 to +0.
 +family=options+0;
 }elseif(options!==undefined&&typeofoptions!=='object'){
 validateFunction(arguments.length===2 ? options : callback,'callback');
 thrownewERR_INVALID_ARG_TYPE('options',['integer','object'],options);
 break;
 default:
 validateOneOf(options.family,'options.family',validFamilies);
 -family=options.family;
 +// Coerce -0 to +0.
 +family=options.family+0;
 break;
+}
+}
 validateFunction(callback,'callback');
 -port=+port;
 +// Coerce -0 to +0.
 +port=+port+0;
 constreq=newGetNameInfoReqWrap();
 req.callback=callback;
-Original file line number
+Diff line change
 }=require('internal/v8/startup_snapshot');
 functionvalidateTimeout(options){
 -const{ timeout =-1}={ ...options};
 +let{ timeout =-1}={ ...options};
 validateInt32(timeout,'options.timeout',-1);
 +// Coerce -0 to +0.
 +timeout+=0;
 returntimeout;
+}
 functionvalidateMaxTimeout(options){
 -const{ maxTimeout =0}={ ...options};
 +let{ maxTimeout =0}={ ...options};
 validateUint32(maxTimeout,'options.maxTimeout');
 +// Coerce -0 to +0.
 +maxTimeout+=0;
 returnmaxTimeout;
+}
-Original file line number
+Diff line change
@@ @@ -0,0 +1,14 @@ @@
 +'use strict';
++
 +constcommon=require('../common');
++
 +constdns=require('dns');
++
 +dns.lookup('localhost',-0,common.mustCall());
 +dns.lookup('localhost',{family: -0},common.mustCall());
 +dns.lookupService('127.0.0.1',-0,common.mustCall());
++
 +newdns.Resolver({timeout: -0});
 +newdns.Resolver({maxTimeout: -0});
++
 +dns.promises.lookup('localhost',{family: -0}).then(common.mustCall());