Fix Bun.inspect null deref with Proxy prototypes; stop reporting from inside the sql lazy-property builders

src/jsc/bindings/BunObject+exports.h

@@ -93,9 +93,16 @@ FOR_EACH_GETTER(DECLARE_ZIG_BUN_OBJECT_GETTER);
 #undef DECLARE_ZIG_BUN_OBJECT_GETTER
 
 // definition of the C++ wrapper to call the Zig function
-#define DEFINE_ZIG_BUN_OBJECT_GETTER_WRAPPER(name) static JSC::JSValue BunObject_lazyPropCb_wrap_##name(JSC::VM &vm, JSC::JSObject *object) { \
-    return JSC::JSValue::decode(BunObject_lazyPropCb_##name(object->globalObject(), object)); \
-} \
+#define DEFINE_ZIG_BUN_OBJECT_GETTER_WRAPPER(name) static JSC::JSValue BunObject_lazyPropCb_wrap_##name(JSC::VM& vm, JSC::JSObject* object) \
+    {                                                                                                                                        \
+        auto scope = DECLARE_THROW_SCOPE(vm);                                                                                                \
+        JSC::JSValue result = JSC::JSValue::decode(BunObject_lazyPropCb_##name(object->globalObject(), object));                            \
+        if (scope.exception()) [[unlikely]] {                                                                                                \
+            (void)scope.tryClearException();                                                                                                \
+            return JSC::jsUndefined();                                                                                                       \
+        }                                                                                                                                    \
+        return result ? result : JSC::jsUndefined();                                                                                        \
+    }
 
 FOR_EACH_GETTER(DEFINE_ZIG_BUN_OBJECT_GETTER_WRAPPER);
 #undef DEFINE_ZIG_BUN_OBJECT_GETTER_WRAPPER

src/jsc/bindings/BunObject.cpp

@@ -311,29 +311,52 @@ static JSValue constructPluginObject(VM& vm, JSObject* bunObject)
     return pluginFunction;
 }
 
+// JSC's reifyStaticProperty passes the PropertyCallback result straight to
+// putDirect without checking for exceptions, and JSValue::get asserts
+// (!scope.exception() || !hasSlot). So these callbacks must not leave a
+// pending exception; if loading the module fails we report it and return
+// jsUndefined() so the property is reified to a valid value.
+static JSValue requireBunSqlModule(VM& vm, Zig::GlobalObject* globalObject, JSC::ThrowScope& scope)
+{
+    JSValue sqlValue = globalObject->internalModuleRegistry()->requireId(globalObject, vm, InternalModuleRegistry::BunSql);
+    if (auto* exception = scope.exception()) [[unlikely]] {
+        (void)scope.tryClearException();
+        globalObject->reportUncaughtExceptionAtEventLoop(globalObject, exception);
+        (void)scope.tryClearException();
+        return {};
+    }
+    if (!sqlValue || !sqlValue.isObject()) [[unlikely]]
+        return {};
+    return sqlValue;
+}
+
 static JSValue defaultBunSQLObject(VM& vm, JSObject* bunObject)
 {
     auto scope = DECLARE_THROW_SCOPE(vm);
     auto* globalObject = defaultGlobalObject(bunObject->globalObject());
-    JSValue sqlValue = globalObject->internalModuleRegistry()->requireId(globalObject, vm, InternalModuleRegistry::BunSql);
-#if BUN_DEBUG
-    if (scope.exception()) globalObject->reportUncaughtExceptionAtEventLoop(globalObject, scope.exception());
-#endif
-    RETURN_IF_EXCEPTION(scope, {});
-    RELEASE_AND_RETURN(scope, sqlValue.getObject()->get(globalObject, vm.propertyNames->defaultKeyword));
+    JSValue sqlValue = requireBunSqlModule(vm, globalObject, scope);
+    if (!sqlValue) return jsUndefined();
+    JSValue result = sqlValue.getObject()->get(globalObject, vm.propertyNames->defaultKeyword);
+    if (scope.exception()) [[unlikely]] {
+        (void)scope.tryClearException();
+        return jsUndefined();
+    }
+    return result ? result : jsUndefined();
 }
 
 static JSValue constructBunSQLObject(VM& vm, JSObject* bunObject)
 {
     auto scope = DECLARE_THROW_SCOPE(vm);
     auto* globalObject = defaultGlobalObject(bunObject->globalObject());
-    JSValue sqlValue = globalObject->internalModuleRegistry()->requireId(globalObject, vm, InternalModuleRegistry::BunSql);
-#if BUN_DEBUG
-    if (scope.exception()) globalObject->reportUncaughtExceptionAtEventLoop(globalObject, scope.exception());
-#endif
-    RETURN_IF_EXCEPTION(scope, {});
+    JSValue sqlValue = requireBunSqlModule(vm, globalObject, scope);
+    if (!sqlValue) return jsUndefined();
     auto clientData = WebCore::clientData(vm);
-    RELEASE_AND_RETURN(scope, sqlValue.getObject()->get(globalObject, clientData->builtinNames().SQLPublicName()));
+    JSValue result = sqlValue.getObject()->get(globalObject, clientData->builtinNames().SQLPublicName());
+    if (scope.exception()) [[unlikely]] {
+        (void)scope.tryClearException();
+        return jsUndefined();
+    }
+    return result ? result : jsUndefined();
 }
 
 extern "C" JSC::EncodedJSValue JSPasswordObject__create(JSGlobalObject*);
@@ -362,25 +385,33 @@ static JSValue constructBunShell(VM& vm, JSObject* bunObject)
     JSC::JSFunction* createShellFn = JSC::JSFunction::create(vm, globalObject, shellCreateBunShellTemplateFunctionCodeGenerator(vm), globalObject);
 
     auto scope = DECLARE_THROW_SCOPE(vm);
+    auto reportAndClear = [&]() {
+        auto* exception = scope.exception();
+        (void)scope.tryClearException();
+        if (exception) globalObject->reportUncaughtExceptionAtEventLoop(globalObject, exception);
+        (void)scope.tryClearException();
+    };
     auto args = JSC::MarkedArgumentBuffer();
     args.append(createShellInterpreterFunction);
     args.append(createParsedShellScript);
     JSC::JSValue shell = JSC::call(globalObject, createShellFn, args, "BunShell"_s);
-    RETURN_IF_EXCEPTION(scope, {});
-
-    if (!shell.isObject()) [[unlikely]] {
-        throwTypeError(globalObject, scope, "Internal error: BunShell constructor did not return an object"_s);
-        return {};
+    if (scope.exception()) [[unlikely]] {
+        reportAndClear();
+        return jsUndefined();
     }
 
+    if (!shell || !shell.isObject()) [[unlikely]]
+        return jsUndefined();
+
     auto* bunShell = shell.getObject();
 
     auto ShellError = bunShell->get(globalObject, JSC::Identifier::fromString(vm, "ShellError"_s));
-    RETURN_IF_EXCEPTION(scope, {});
-    if (!ShellError.isObject()) [[unlikely]] {
-        throwTypeError(globalObject, scope, "Internal error: BunShell.ShellError is not an object"_s);
-        return {};
+    if (scope.exception()) [[unlikely]] {
+        reportAndClear();
+        return jsUndefined();
     }
+    if (!ShellError || !ShellError.isObject()) [[unlikely]]
+        return jsUndefined();
 
     bunShell->putDirectNativeFunction(vm, globalObject, Identifier::fromString(vm, "braces"_s), 1, Generated::BunObject::jsBraces, ImplementationVisibility::Public, NoIntrinsic, JSC::PropertyAttribute::DontDelete | JSC::PropertyAttribute::ReadOnly | 0);
     bunShell->putDirectNativeFunction(vm, globalObject, Identifier::fromString(vm, "escape"_s), 1, BunObject_callback_shellEscape, ImplementationVisibility::Public, NoIntrinsic, JSC::PropertyAttribute::DontDelete | JSC::PropertyAttribute::ReadOnly | 0);

src/jsc/bindings/bindings.cpp

@@ -5369,10 +5369,11 @@ static void JSC__JSValue__forEachPropertyImpl(JSC::EncodedJSValue JSValue0, JSC:
                 }
 
                 JSC::PropertySlot slot(object, PropertySlot::InternalMethodType::Get);
-                if (!object->getPropertySlot(globalObject, property, slot))
-                    continue;
+                bool found = object->getPropertySlot(globalObject, property, slot);
                 // Ignore exceptions from "Get" proxy traps.
                 CLEAR_IF_EXCEPTION(scope);
+                if (!found)
+                    continue;
 
                 if ((slot.attributes() & PropertyAttribute::DontEnum) != 0) {
                     if (property == propertyNames->underscoreProto
@@ -5444,7 +5445,10 @@ static void JSC__JSValue__forEachPropertyImpl(JSC::EncodedJSValue JSValue0, JSC:
                 break;
             if (iterating == globalObject)
                 break;
-            iterating = iterating->getPrototype(globalObject).getObject();
+            JSValue proto = iterating->getPrototype(globalObject);
+            // Ignore exceptions from Proxy "getPrototypeOf" trap.
+            CLEAR_IF_EXCEPTION(scope);
+            iterating = proto ? proto.getObject() : nullptr;
         }
     }
 

test/js/bun/util/inspect.test.js

@@ -2,6 +2,41 @@ import { describe, expect, it } from "bun:test";
 import { normalizeBunSnapshot, tmpdirSync } from "harness";
 import { join } from "path";
 import util from "util";
+
+it("Proxy prototype with throwing getPrototypeOf trap does not crash", () => {
+  const obj = {};
+  Object.setPrototypeOf(
+    obj,
+    new Proxy(
+      {},
+      {
+        getPrototypeOf() {
+          throw new Error("trap threw");
+        },
+      },
+    ),
+  );
+  expect(() => Bun.inspect(obj)).not.toThrow();
+});
+
+it("Proxy prototype with throwing getter does not crash", () => {
+  const obj = {};
+  Object.setPrototypeOf(
+    obj,
+    new Proxy(
+      {
+        get x() {
+          throw new Error("getter threw");
+        },
+        foo: 1,
+      },
+      {},
+    ),
+  );
+  const out = Bun.inspect(obj);
+  expect(out).toContain("foo");
+});
+
 it("prototype", () => {
   const prototypes = [
     Request.prototype,

test/regression/issue/19650.test.ts

@@ -0,0 +1,51 @@
+import { expect, test } from "bun:test";
+import { bunEnv, bunExe } from "harness";
+
+// Several lazy PropertyCallback entries on the Bun object (Bun.$, Bun.sql,
+// Bun.SQL, ...) run JS on first access. If that JS throws (e.g. a stack
+// overflow), the callback previously returned an empty JSValue, which JSC's
+// reifyStaticProperty passes straight to putDirect without an exception
+// check, crashing on a null JSCell dereference.
+test.concurrent.each(["$", "sql", "SQL", "postgres"] as const)(
+  "accessing Bun.%s near stack overflow does not crash",
+  async key => {
+    const src = `
+      function F() {
+        try { new F(); } catch {}
+        Bun[${JSON.stringify(key)}];
+      }
+      try { new F(); } catch {}
+      Bun.gc(true);
+    `;
+    await using proc = Bun.spawn({
+      cmd: [bunExe(), "-e", src],
+      env: bunEnv,
+      stdout: "ignore",
+      stderr: "ignore",
+    });
+    const exitCode = await proc.exited;
+    expect(proc.signalCode).toBeNull();
+    expect([0, 1]).toContain(exitCode);
+  },
+);
+
+test.concurrent.each(["$", "sql", "SQL", "postgres"] as const)(
+  "accessing Bun.%s after clobbering Symbol does not crash",
+  async key => {
+    const src = `
+      globalThis.Symbol = NaN;
+      try { Bun[${JSON.stringify(key)}]; } catch {}
+      try { Bun[${JSON.stringify(key)}]; } catch {}
+      Bun.gc(true);
+    `;
+    await using proc = Bun.spawn({
+      cmd: [bunExe(), "-e", src],
+      env: bunEnv,
+      stdout: "ignore",
+      stderr: "ignore",
+    });
+    const exitCode = await proc.exited;
+    expect(proc.signalCode).toBeNull();
+    expect([0, 1]).toContain(exitCode);
+  },
+);