From 3164ef34a5ee2937ecd7cf03b85e6a25952773ba Mon Sep 17 00:00:00 2001
From: tt-a1i <53142663+tt-a1i@users.noreply.github.com>
Date: Tue, 23 Jun 2026 03:37:44 +0800
Subject: [PATCH] fix(serve): reject fractional max connections

---
 packages/cli/src/serve/run-qwen-serve.ts | 11 ++++++-----
 packages/cli/src/serve/server.test.ts    | 20 ++++++++------------
 2 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/packages/cli/src/serve/run-qwen-serve.ts b/packages/cli/src/serve/run-qwen-serve.ts
index bd712c7730c..82d00b01a2a 100644
--- a/packages/cli/src/serve/run-qwen-serve.ts
+++ b/packages/cli/src/serve/run-qwen-serve.ts
@@ -1158,14 +1158,15 @@ export async function runQwenServe(
   // promise instead of escaping as an uncaught exception inside the
   // listen callback (which fires from the `listening` event after the
   // outer promise has already resolved). Silent fail-OPEN on NaN /
-  // negative would weaken the DoS/FD-exhaustion guard the cap exists
-  // for.
+  // negative / fractional values would weaken or blur the
+  // DoS/FD-exhaustion guard the cap exists for.
   if (
     opts.maxConnections !== undefined &&
-    (Number.isNaN(opts.maxConnections) || opts.maxConnections < 0)
+    !isNonNegativeIntegerOrInfinity(opts.maxConnections)
   ) {
     throw new TypeError(
-      `Invalid maxConnections: ${opts.maxConnections}. Must be >= 0 ` +
+      `Invalid maxConnections: ${opts.maxConnections}. ` +
+        `Must be a non-negative integer ` +
         `(0 / Infinity = unlimited).`,
     );
   }
@@ -1190,7 +1191,7 @@ export async function runQwenServe(
       // with `SocketError: other side closed`). Treat 0 / Infinity
       // as "leave the property unset" so the documented disable
       // path actually disables instead of silently bricking the
-      // daemon. NaN / negative are rejected upstream so
+      // daemon. NaN / negative / fractional values are rejected upstream so
       // they never reach here.
       const cap = opts.maxConnections ?? 256;
       if (cap > 0 && Number.isFinite(cap)) {
diff --git a/packages/cli/src/serve/server.test.ts b/packages/cli/src/serve/server.test.ts
index 72e0dae3146..f2d4fd6aa81 100644
--- a/packages/cli/src/serve/server.test.ts
+++ b/packages/cli/src/serve/server.test.ts
@@ -8970,7 +8970,7 @@ describe('runQwenServe', () => {
     // Node 22 `server.maxConnections = 0` causes the listener to
     // refuse EVERY connection. An operator following the documented
     // disable path got a daemon that booted cleanly but silently
-    // bricked every request. Fix treats 0 / Infinity / non-finite as
+    // bricked every request. Fix treats 0 / Infinity as
     // "leave the property unset" so Node's default (no cap) actually
     // applies.
     handle = await runQwenServe({
@@ -9012,7 +9012,11 @@ describe('runQwenServe', () => {
     expect(handle.server.maxConnections).toBe(100);
   });
 
-  it('--max-connections NaN/negative throws at boot (BUF9-)', async () => {
+  it.each([
+    ['NaN', NaN],
+    ['negative', -5],
+    ['fractional', 1.5],
+  ])('--max-connections %s throws at boot (BUF9-)', async (_label, value) => {
     // Silent fail-OPEN on a CLI typo would weaken the DoS guard.
     // Boot-loud is the right behavior for an unparseable cap.
     await expect(
@@ -9020,17 +9024,9 @@ describe('runQwenServe', () => {
         hostname: '127.0.0.1',
         port: 0,
         mode: 'http-bridge',
-        maxConnections: NaN,
-      }),
-    ).rejects.toThrow(/maxConnections: NaN/);
-    await expect(
-      runQwenServe({
-        hostname: '127.0.0.1',
-        port: 0,
-        mode: 'http-bridge',
-        maxConnections: -5,
+        maxConnections: value,
       }),
-    ).rejects.toThrow(/maxConnections: -5/);
+    ).rejects.toThrow(/maxConnections/);
   });
 
   it('case-insensitive loopback: --hostname Localhost / LOCALHOST does NOT require a token (BQ92B)', async () => {