src,permission: add --permission-audit

Add --permission-audit flag that enables the permission model in
warning-only mode. Instead of throwing ERR_ACCESS_DENIED, it emits
a message via diagnostics channel and allows the operation to
continue.
Publish permission check results to per-scope diagnostics channels
(e.g., node:permission-model:fs) so users can observe permission
decisions at runtime via diagnostics_channel.
Refs: #59935
PR-URL: #61869
Backport-PR-URL: #65354
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: RafaelGSS

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');

doc/api/cli.md

@@ -2137,6 +2137,16 @@ following permissions are restricted:
 * WASI - manageable through [`--allow-wasi`][] flag
 * Addons - manageable through [`--allow-addons`][] flag
 
+### `--permission-audit`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+
 ### `--preserve-symlinks`
 
 <!-- YAML
@@ -3661,6 +3671,7 @@ one is included in the list below.
 *`--openssl-legacy-provider`
 *`--openssl-shared-config`
 *`--pending-deprecation`
+*`--permission-audit`
 *`--permission`
 *`--preserve-symlinks-main`
 *`--preserve-symlinks`

doc/node.1

@@ -468,6 +468,11 @@ Among other uses, this can be used to enable FIPS-compliant crypto if Node.js is
 .ItFl-pending-deprecation
 Emit pending deprecation warnings.
 .
+.ItFl-permission-audit
+Enable audit only for the permission model. When enabled, permission checks
+are performed but access is not denied. Instead, a warning is emitted for
+each permission violation via diagnostics channel.
+.
 .ItFl-preserve-symlinks
 Instructs the module loader to preserve symbolic links when resolving and caching modules other than the main module.
 .

lib/internal/process/pre_execution.js

@@ -634,7 +634,7 @@ function setupDiagnosticsChannel() {
 }
 
 functioninitializePermission(){
-constpermission=getOptionValue('--permission');
+constpermission=getOptionValue('--permission')||getOptionValue('--permission-audit');
 if(permission){
 process.binding=functionbinding(_module){
 thrownewERR_ACCESS_DENIED('process.binding');

src/env.cc

@@ -900,8 +900,11 @@ Environment::Environment(IsolateData* isolate_data,
 tracing::CastTracedValue(traced_value));
  }
 
-if (options_->permission) {
+if (options_->permission || options_->permission_audit) {
 permission()->EnablePermissions();
+if (options_->permission_audit) {
+permission()->EnableWarningOnly();
+ }
 // The process shouldn't be able to neither
 // spawn/worker nor use addons or enable inspector
 // unless explicitly allowed by the user

src/node_options.cc

@@ -639,6 +639,11 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
  &EnvironmentOptions::permission,
 kAllowedInEnvvar,
 false);
+AddOption("--permission-audit",
+"enable audit only for the permission system",
+ &EnvironmentOptions::permission_audit,
+kAllowedInEnvvar,
+false);
 AddOption("--allow-fs-read",
 "allow permissions to read the filesystem",
  &EnvironmentOptions::allow_fs_read,

src/node_options.h

@@ -143,6 +143,7 @@ class EnvironmentOptions : public Options {
  std::string input_type; // Value of --input-type
 bool entry_is_url = false;
 bool permission = false;
+bool permission_audit = false;
  std::vector<std::string> allow_fs_read;
  std::vector<std::string> allow_fs_write;
 bool allow_addons = false;

src/permission/permission.cc

@@ -3,6 +3,7 @@
 #include"env-inl.h"
 #include"memory_tracker-inl.h"
 #include"node.h"
+#include"node_diagnostics_channel.h"
 #include"node_errors.h"
 #include"node_external_reference.h"
 #include"node_file.h"
@@ -27,6 +28,27 @@ namespace permission {
 
 namespace {
 
+constexpr std::string_view GetDiagnosticsChannelName(PermissionScope scope) {
+switch (scope) {
+case PermissionScope::kFileSystem:
+case PermissionScope::kFileSystemRead:
+case PermissionScope::kFileSystemWrite:
+return"node:permission-model:fs";
+case PermissionScope::kChildProcess:
+return"node:permission-model:child";
+case PermissionScope::kWorkerThreads:
+return"node:permission-model:worker";
+case PermissionScope::kInspector:
+return"node:permission-model:inspector";
+case PermissionScope::kWASI:
+return"node:permission-model:wasi";
+case PermissionScope::kAddon:
+return"node:permission-model:addon";
+default:
+return {};
+ }
+}
+
 // permission.has('fs.in', '/tmp/')
 // permission.has('fs.in')
 staticvoidHas(const FunctionCallbackInfo<Value>& args) {
@@ -70,7 +92,7 @@ PermissionScope Permission::StringToPermission(const std::string& perm) {
 }
 #undef V
 
-Permission::Permission() : enabled_(false) {
+Permission::Permission() : enabled_(false), warning_only_(false) {
  std::shared_ptr<PermissionBase> fs = std::make_shared<FSPermission>();
  std::shared_ptr<PermissionBase> child_p =
  std::make_shared<ChildProcessPermission>();
@@ -170,6 +192,74 @@ void Permission::EnablePermissions() {
  }
 }
 
+voidPermission::EnableWarningOnly() {
+if (!warning_only_) {
+ warning_only_ = true;
+ }
+}
+
+boolPermission::is_scope_granted(Environment* env,
+const PermissionScope permission,
+const std::string_view& res) const {
+auto perm_node = nodes_.find(permission);
+bool result = false;
+if (perm_node != nodes_.end()) {
+ result = perm_node->second->is_granted(env, permission, res);
+ }
+
+if (!result && !publishing_) {
+auto channel_name = GetDiagnosticsChannelName(permission);
+if (!channel_name.empty()) {
+auto ch = GetOrCreateChannel(env, permission);
+if (ch && ch->HasSubscribers()) {
+ publishing_ = true;
+ v8::Isolate* isolate = env->isolate();
+ v8::HandleScope handle_scope(isolate);
+ v8::Local<v8::Context> context = env->context();
+ v8::Local<v8::Object> msg =
+v8::Object::New(isolate, v8::Null(isolate), nullptr, nullptr, 0);
+constchar* perm_str = PermissionToString(permission);
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "permission"),
+v8::String::NewFromUtf8(isolate, perm_str).ToLocalChecked())
+ .Check();
+ msg->Set(context,
+FIXED_ONE_BYTE_STRING(isolate, "resource"),
+v8::String::NewFromUtf8(isolate,
+ res.data(),
+ v8::NewStringType::kNormal,
+static_cast<int>(res.size()))
+ .ToLocalChecked())
+ .Check();
+ ch->Publish(env, msg);
+ publishing_ = false;
+ }
+ }
+ }
+
+return result;
+}
+
+BaseObjectPtr<diagnostics_channel::Channel> Permission::GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const {
+auto it = channels_.find(scope);
+if (it != channels_.end()) {
+// Promote weak ref to strong for the duration of this call.
+ BaseObjectPtr<diagnostics_channel::Channel> ptr(it->second.get());
+if (ptr) return ptr;
+ channels_.erase(it);
+ }
+auto channel_name = GetDiagnosticsChannelName(scope);
+ diagnostics_channel::Channel* ch =
+diagnostics_channel::Channel::Get(env, channel_name.data());
+if (ch != nullptr) {
+ channels_.emplace(scope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>(ch));
+return BaseObjectPtr<diagnostics_channel::Channel>(ch);
+ }
+return {};
+}
+
 voidPermission::Apply(Environment* env,
 const std::vector<std::string>& allow,
  PermissionScope scope) {

src/permission/permission.h

@@ -4,6 +4,7 @@
 #if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
 
 #include"debug_utils.h"
+#include"node_diagnostics_channel.h"
 #include"node_options.h"
 #include"permission/addon_permission.h"
 #include"permission/child_process_permission.h"
@@ -36,7 +37,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::ThrowAccessDenied( \
  env__, perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -50,7 +51,7 @@ namespace permission {
 [[unlikely]] { \
 node::permission::Permission::AsyncThrowAccessDenied( \
  env__, (wrap), perm__, resource__); \
-return __VA_ARGS__; \
+if (!env__->permission()->warning_only()) return __VA_ARGS__; \
  } \
  } while (0)
 
@@ -99,6 +100,8 @@ class Permission {
 
 FORCE_INLINEboolenabled() const { return enabled_; }
 
+FORCE_INLINEboolwarning_only() const { return warning_only_; }
+
 static PermissionScope StringToPermission(const std::string& perm);
 staticconstchar* PermissionToString(PermissionScope perm);
 staticvoidThrowAccessDenied(Environment* env,
@@ -114,20 +117,25 @@ class Permission {
 const std::vector<std::string>& allow,
  PermissionScope scope);
 voidEnablePermissions();
+voidEnableWarningOnly();
 
 private:
 COLD_NOINLINEboolis_scope_granted(Environment* env,
 const PermissionScope permission,
-const std::string_view& res = "") const {
-auto perm_node = nodes_.find(permission);
-if (perm_node != nodes_.end()) {
-return perm_node->second->is_granted(env, permission, res);
- }
-returnfalse;
- }
+const std::string_view& res = "") const;
+
+ BaseObjectPtr<diagnostics_channel::Channel> GetOrCreateChannel(
+ Environment* env, PermissionScope scope) const;
 
  std::unordered_map<PermissionScope, std::shared_ptr<PermissionBase>> nodes_;
 bool enabled_;
+bool warning_only_;
+mutablebool publishing_ = false;
+// Weak refs: BindingData (via BaseObjectPtr) is the sole owner of Channels.
+// Using weak refs here avoids keeping Channels alive past Realm teardown.
+mutable std::unordered_map<PermissionScope,
+ BaseObjectWeakPtr<diagnostics_channel::Channel>>
+ channels_;
 };
 
 } // namespace permission

test/parallel/test-permission-diagnostics-channel.js

@@ -0,0 +1,29 @@
+// Flags: --permission --allow-fs-read=*
+'use strict';
+
+constcommon=require('../common');
+const{ isMainThread }=require('worker_threads');
+
+if(!isMainThread){
+common.skip('This test only works on a main thread');
+}
+
+constassert=require('node:assert');
+constdc=require('node:diagnostics_channel');
+constfs=require('node:fs');
+
+constmessages=[];
+dc.subscribe('node:permission-model:fs',(msg)=>{
+messages.push(msg);
+});
+
+// Granted permission should not publish
+fs.readFileSync(__filename);
+assert.strictEqual(messages.length,0);
+
+// Denied permission should publish
+consthasWrite=process.permission.has('fs.write','/tmp/test');
+assert.strictEqual(hasWrite,false);
+
+assert.ok(messages.length>0,'Expected at least one denied message');
+assert.strictEqual(messages[0].permission,'FileSystemWrite');