fix(runtime): fix dns_resolver crash (#4435)

* fix incorrect c pointer

* format

* lets go

* random other test case fixed

* hanassagi patch

* Update dns_resolver.zig

* Revert "Update dns_resolver.zig"

This reverts commit 53eb338048583a338e7c01d2b351f1c679db3e15.

* See if the tests pass

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>
Co-authored-by: Jarred Sumner <jarred@jarredsumner.com>

3 files changed, 19 insertions, 17 deletions

diff --git a/src/bun.js/api/bun/dns_resolver.zig b/src/bun.js/api/bun/dns_resolver.zig
index 7364c2ffa..8232318a2 100644
--- a/src/bun.js/api/bun/dns_resolver.zig
+++ b/src/bun.js/api/bun/dns_resolver.zig
@@ -1497,8 +1497,10 @@ pub const DNSResolver = struct {
 
         var pending: ?*CAresReverse = key.lookup.head.next;
         var prev_global = key.lookup.head.globalThis;
+        //  The callback need not and should not attempt to free the memory
+        //  pointed to by hostent; the ares library will free it when the
+        //  callback returns.
         var array = addr.toJSReponse(this.vm.allocator, prev_global, "");
-        defer addr.deinit();
         array.ensureStillAlive();
         key.lookup.head.onComplete(array);
         bun.default_allocator.destroy(key.lookup);
@@ -2320,7 +2322,7 @@ pub const DNSResolver = struct {
             },
         };
 
-        var servers: [*c]c_ares.struct_ares_addr_port_node = undefined;
+        var servers: ?*c_ares.struct_ares_addr_port_node = null;
         const r = c_ares.ares_get_servers_ports(channel, &servers);
         if (r != c_ares.ARES_SUCCESS) {
             const err = c_ares.Error.get(r).?;
@@ -2333,21 +2335,21 @@ pub const DNSResolver = struct {
 
         var i: u32 = 0;
         var cur = servers;
-        while (cur != null) : ({
+        while (cur) |current| : ({
             i += 1;
-            cur = cur.*.next;
+            cur = current.next;
         }) {
             // Formatting reference: https://nodejs.org/api/dns.html#dnsgetservers
             // Brackets '[' and ']' consume 2 bytes, used for IPv6 format (e.g., '[2001:4860:4860::8888]:1053').
             // Port range is 6 bytes (e.g., ':65535').
             // Null terminator '\0' uses 1 byte.
             var buf: [INET6_ADDRSTRLEN + 2 + 6 + 1]u8 = undefined;
-            const family = cur.*.family;
+            const family = current.family;
 
             const ip = if (family == std.os.AF.INET6) blk: {
-                break :blk c_ares.ares_inet_ntop(family, &cur.*.addr.addr6, buf[1..], @sizeOf(@TypeOf(buf)) - 1);
+                break :blk c_ares.ares_inet_ntop(family, &current.addr.addr6, buf[1..], @sizeOf(@TypeOf(buf)) - 1);
             } else blk: {
-                break :blk c_ares.ares_inet_ntop(family, &cur.*.addr.addr4, buf[1..], @sizeOf(@TypeOf(buf)) - 1);
+                break :blk c_ares.ares_inet_ntop(family, &current.addr.addr4, buf[1..], @sizeOf(@TypeOf(buf)) - 1);
             };
             if (ip == null) {
                 globalThis.throwValue(globalThis.createErrorInstance(
@@ -2357,15 +2359,15 @@ pub const DNSResolver = struct {
                 return .zero;
             }
 
-            var port = cur.*.tcp_port;
+            var port = current.tcp_port;
             if (port == 0) {
-                port = cur.*.udp_port;
+                port = current.udp_port;
             }
             if (port == 0) {
                 port = IANA_DNS_PORT;
             }
 
-            const size = bun.len(bun.cast([*:0]u8, &buf));
+            const size = bun.len(bun.cast([*:0]u8, buf[1..])) + 1;
             if (port == IANA_DNS_PORT) {
                 values.putIndex(globalThis, i, JSC.ZigString.init(buf[1..size]).withEncoding().toValueGC(globalThis));
             } else {
diff --git a/src/deps/c_ares.zig b/src/deps/c_ares.zig
index b80342996..5098f4e19 100644
--- a/src/deps/c_ares.zig
+++ b/src/deps/c_ares.zig
@@ -1167,7 +1167,7 @@ const union_unnamed_3 = extern union {
     addr6: struct_ares_in6_addr,
 };
 pub const struct_ares_addr_node = extern struct {
-    next: [*c]struct_ares_addr_node,
+    next: ?*struct_ares_addr_node,
     family: c_int,
     addr: union_unnamed_3,
 };
@@ -1176,7 +1176,7 @@ const union_unnamed_4 = extern union {
     addr6: struct_ares_in6_addr,
 };
 pub const struct_ares_addr_port_node = extern struct {
-    next: [*c]struct_ares_addr_port_node,
+    next: ?*struct_ares_addr_port_node,
     family: c_int,
     addr: union_unnamed_4,
     udp_port: c_int,
@@ -1186,8 +1186,8 @@ pub extern fn ares_set_servers(channel: *Channel, servers: [*c]struct_ares_addr_
 pub extern fn ares_set_servers_ports(channel: *Channel, servers: [*c]struct_ares_addr_port_node) c_int;
 pub extern fn ares_set_servers_csv(channel: *Channel, servers: [*c]const u8) c_int;
 pub extern fn ares_set_servers_ports_csv(channel: *Channel, servers: [*c]const u8) c_int;
-pub extern fn ares_get_servers(channel: *Channel, servers: [*c][*c]struct_ares_addr_node) c_int;
-pub extern fn ares_get_servers_ports(channel: *Channel, servers: [*c][*c]struct_ares_addr_port_node) c_int;
+pub extern fn ares_get_servers(channel: *Channel, servers: *?*struct_ares_addr_port_node) c_int;
+pub extern fn ares_get_servers_ports(channel: *Channel, servers: *?*struct_ares_addr_port_node) c_int;
 pub extern fn ares_inet_ntop(af: c_int, src: ?*const anyopaque, dst: [*c]u8, size: ares_socklen_t) [*c]const u8;
 pub extern fn ares_inet_pton(af: c_int, src: [*c]const u8, dst: ?*anyopaque) c_int;
 pub const ARES_SUCCESS = 0;
diff --git a/test/cli/bun.test.ts b/test/cli/bun.test.ts
index 6deedcec8..5c5715168 100644
--- a/test/cli/bun.test.ts
+++ b/test/cli/bun.test.ts
@@ -1,6 +1,6 @@
 import { describe, test, expect } from "bun:test";
 import { spawnSync } from "bun";
-import { bunExe } from "harness";
+import { bunEnv, bunExe } from "harness";
 import { tmpdir } from "node:os";
 import fs from "node:fs";
 
@@ -39,14 +39,14 @@ describe("bun", () => {
     test("revision generates version numbers correctly", () => {
       var { stdout, exitCode } = Bun.spawnSync({
         cmd: [bunExe(), "--version"],
-        env: {},
+        env: bunEnv,
         stderr: "inherit",
       });
       var version = stdout.toString().trim();
 
       var { stdout, exitCode } = Bun.spawnSync({
         cmd: [bunExe(), "--revision"],
-        env: {},
+        env: bunEnv,
         stderr: "inherit",
       });
       var revision = stdout.toString().trim();