From: Dmitry Volyntsev <xeioex@nginx.com>
Date: Thu, 5 Nov 2026 00:49:18 +0000 (-0800)
Subject: Modules: reject asynchronous work during module initialization
X-Git-Url: https://git.kaiwu.me/%7B@url%7D?a=commitdiff_plain;h=72774fc2deabcf87f8d016a6fb76dda0142c64ee;p=njs.git

Modules: reject asynchronous work during module initialization

Global code is intended for synchronous initialization, but Fetch and
timers could start request-bound work before clone publication.  QuickJS
Fetch dereferenced the unpublished engine, and module-level timers could
escape initialization.

Reject Fetch, setTimeout(), and setImmediate() before argument conversion
or resource allocation in both engines.  This does not prohibit ordinary
promise jobs or synchronous module initialization.
---

diff --git a/nginx/ngx_js.c b/nginx/ngx_js.c
index 523799c3..282af631 100644
--- a/nginx/ngx_js.c
+++ b/nginx/ngx_js.c
@@ -1832,6 +1832,13 @@ ngx_qjs_ext_set_timeout(JSContext *cx, JSValueConst this_val, int argc,
     ngx_qjs_event_t   *event;
     ngx_connection_t  *c;
 
+    external = JS_GetContextOpaque(cx);
+    ctx = ngx_qjs_external_ctx(cx, external);
+    if (ctx->engine == NULL) {
+        return JS_ThrowTypeError(cx, "async operations are not allowed "
+                                    "during module initialization");
+    }
+
     if (!JS_IsFunction(cx, argv[0])) {
         return JS_ThrowTypeError(cx, "first arg must be a function");
     }
@@ -1846,9 +1853,6 @@ ngx_qjs_ext_set_timeout(JSContext *cx, JSValueConst this_val, int argc,
 
     n = immediate ? 1 : 2;
     argc = (argc >= n) ? argc - n : 0;
-    external = JS_GetContextOpaque(cx);
-    ctx = ngx_qjs_external_ctx(cx, external);
-
     event = ngx_pcalloc(ngx_qjs_external_pool(cx, external),
                         sizeof(ngx_qjs_event_t) + sizeof(JSValue) * argc);
     if (event == NULL) {
@@ -3285,6 +3289,13 @@ njs_set_timer(njs_vm_t *vm, njs_value_t *args, njs_uint_t nargs,
     ngx_js_event_t    *event;
     ngx_connection_t  *c;
 
+    ctx = ngx_external_ctx(vm, njs_vm_external_ptr(vm));
+    if (ctx->engine == NULL) {
+        njs_vm_type_error(vm, "async operations are not allowed "
+                             "during module initialization");
+        return NJS_ERROR;
+    }
+
     if (njs_slow_path(nargs < 2)) {
         njs_vm_type_error(vm, "too few arguments");
         return NJS_ERROR;
@@ -3320,7 +3331,6 @@ njs_set_timer(njs_vm_t *vm, njs_value_t *args, njs_uint_t nargs,
     event->args = (njs_opaque_value_t *) &event[1];
     event->destructor = ngx_js_clear_timer;
 
-    ctx = ngx_external_ctx(vm, njs_vm_external_ptr(vm));
     event->fd = ctx->event_id++;
 
     c = ngx_external_connection(vm, njs_vm_external_ptr(vm));
diff --git a/nginx/ngx_js_fetch.c b/nginx/ngx_js_fetch.c
index 003ded35..73abe8ff 100644
--- a/nginx/ngx_js_fetch.c
+++ b/nginx/ngx_js_fetch.c
@@ -510,6 +510,7 @@ ngx_js_ext_fetch(njs_vm_t *vm, njs_value_t *args, njs_uint_t nargs,
     ngx_str_t           *resolve_host;
     ngx_pool_t          *pool;
     njs_value_t         *init, *value;
+    ngx_js_ctx_t        *jsctx;
     ngx_js_http_t       *http;
     ngx_js_fetch_t      *fetch;
     ngx_js_request_t     request;
@@ -525,6 +526,13 @@ ngx_js_ext_fetch(njs_vm_t *vm, njs_value_t *args, njs_uint_t nargs,
 #endif
 
     external = njs_vm_external_ptr(vm);
+    jsctx = ngx_external_ctx(vm, external);
+    if (jsctx->engine == NULL) {
+        njs_vm_type_error(vm, "async operations are not allowed "
+                             "during module initialization");
+        return NJS_ERROR;
+    }
+
     c = ngx_external_connection(vm, external);
     pool = ngx_external_pool(vm, external);
 
diff --git a/nginx/ngx_qjs_fetch.c b/nginx/ngx_qjs_fetch.c
index 7149b976..ff34dd55 100644
--- a/nginx/ngx_qjs_fetch.c
+++ b/nginx/ngx_qjs_fetch.c
@@ -257,6 +257,12 @@ ngx_qjs_ext_fetch(JSContext *cx, JSValueConst this_val, int argc,
     ngx_resolver_ctx_t  *rs;
 
     external = JS_GetContextOpaque(cx);
+    ctx = ngx_qjs_external_ctx(cx, external);
+    if (ctx->engine == NULL) {
+        return JS_ThrowTypeError(cx, "async operations are not allowed "
+                                    "during module initialization");
+    }
+
     c = ngx_qjs_external_connection(cx, external);
     pool = ngx_qjs_external_pool(cx, external);
 
@@ -353,8 +359,6 @@ ngx_qjs_ext_fetch(JSContext *cx, JSValueConst this_val, int argc,
         http->header_only = 1;
     }
 
-    ctx = ngx_qjs_external_ctx(cx, JS_GetContextOpaque(cx));
-
     NJS_CHB_MP_INIT(&http->chain, ctx->engine->pool);
     NJS_CHB_MP_INIT(&http->response.chain, ctx->engine->pool);