console: guard AggregateError .errors recursion (cycle, depth, tampered property)

src/jsc/VirtualMachine.rs

@@ -4469,6 +4469,7 @@ impl VirtualMachine {
         allow_side_effects: bool,
     ) {
         let mut formatter = crate::console_object::Formatter::new(self.global());
+        formatter.stack_check = bun_core::util::StackCheck::init();
         let colors = bun_core::Output::enable_ansi_colors_stderr();
         self.print_errorlike_object(
             exception.value(),
@@ -4784,7 +4785,59 @@ impl VirtualMachine {
         // once the AggregateError branch is taken).
         let global_ref = self.global();
 
-        if value.is_aggregate_error(global_ref) {
+        let is_aggregate = value.is_aggregate_error(global_ref);
+        if is_aggregate {
+            use crate::console_object::formatter::visited;
+
+            // Depth guard: this branch re-enters through `agg_iter` below with
+            // no intervening JSC stack check.
+            if !formatter.stack_check.is_safe_to_recurse() {
+                let marker = if allow_ansi_color {
+                    bun_core::pretty_fmt!("<r><cyan>[AggregateError: nesting too deep]<r>\n", true)
+                } else {
+                    bun_core::pretty_fmt!("<r><cyan>[AggregateError: nesting too deep]<r>\n", false)
+                };
+                let _ = writer.write_all(marker.as_bytes());
+                return;
+            }
+
+            // Circular-ref guard keyed on the AggregateError object identity,
+            // same visited pool the cause-chain and object printers use.
+            if formatter.map_node.is_none() {
+                let mut node = NonNull::new(visited::Pool::get_node())
+                    .expect("ObjectPool::get_node always returns a valid heap node");
+                let data = visited::node_data_mut(&mut node);
+                data.clear();
+                formatter.map = core::mem::take(data);
+                formatter.map_node = Some(node);
+            }
+            let entry = formatter.map.get_or_put(value).expect("unreachable");
+            if entry.found_existing {
+                let marker = if allow_ansi_color {
+                    bun_core::pretty_fmt!("<r><cyan>[Circular]<r>\n", true)
+                } else {
+                    bun_core::pretty_fmt!("<r><cyan>[Circular]<r>\n", false)
+                };
+                let _ = writer.write_all(marker.as_bytes());
+                return;
+            }
+            // Fall through so the AggregateError's own name/message/stack is
+            // printed before its children.
+        }
+
+        // Note: reborrow so the add-to-error-list tail can still see it after
+        // `print_error_from_maybe_private_data`.
+        let mut exception_list = exception_list;
+        let was_internal = self.print_error_from_maybe_private_data(
+            value,
+            exception_list.as_deref_mut(),
+            formatter,
+            writer,
+            allow_ansi_color,
+            allow_side_effects,
+        );
+
+        if is_aggregate {
             // Note: `JSValue::for_each` takes a C-ABI fn
             // pointer + erased ctx, so thread the captures through a struct.
             // The C trampoline erases lifetimes via `*mut c_void`; round-trip
@@ -4830,35 +4883,31 @@ impl VirtualMachine {
                     ctx.allow_side_effects,
                 );
             }
-            let mut ctx = AggCtx {
-                formatter: std::ptr::from_mut(formatter),
-                writer: std::ptr::from_mut(writer),
-                exception_list: exception_list
-                    .map(std::ptr::from_mut::<ExceptionList>)
-                    .unwrap_or(core::ptr::null_mut()),
-                allow_ansi_color,
-                allow_side_effects,
-            };
-            // `getErrorsProperty` is
-            // `getDirect` (own data prop, nothrow); `for_each` may throw, in
-            // which case the error is swallowed.
+            // `getErrorsProperty` is `getDirect` (own data prop, nothrow), so
+            // a deleted or accessor `errors` surfaces here as empty / a
+            // GetterSetter cell.
             let errors = value.get_errors_property(global_ref);
-            let _ = errors.for_each(global_ref, (&raw mut ctx).cast(), agg_iter);
+            if errors.is_object() {
+                let mut ctx = AggCtx {
+                    formatter: std::ptr::from_mut(formatter),
+                    writer: std::ptr::from_mut(writer),
+                    exception_list: exception_list
+                        .map(std::ptr::from_mut::<ExceptionList>)
+                        .unwrap_or(core::ptr::null_mut()),
+                    allow_ansi_color,
+                    allow_side_effects,
+                };
+                if errors
+                    .for_each(global_ref, (&raw mut ctx).cast(), agg_iter)
+                    .is_err()
+                {
+                    self.global().clear_exception();
+                }
+            }
+            let _ = formatter.map.remove(&value);
             return;
         }
 
-        // Note: reborrow so the add-to-error-list tail can still see it after
-        // `print_error_from_maybe_private_data`.
-        let mut exception_list = exception_list;
-        let was_internal = self.print_error_from_maybe_private_data(
-            value,
-            exception_list.as_deref_mut(),
-            formatter,
-            writer,
-            allow_ansi_color,
-            allow_side_effects,
-        );
-
         if was_internal {
             if let Some(exception_) = exception {
                 let mut holder = crate::zig_exception::Holder::init();

src/runtime/jsc_hooks.rs

@@ -1194,6 +1194,7 @@ fn print_exception(
         vm_ref.print_exception(exception, exception_list, writer, true);
     } else {
         let mut formatter = bun_jsc::console_object::Formatter::new(global);
+        formatter.stack_check = bun_core::util::StackCheck::init();
         // `Formatter::new` already
         // defaults `error_display_level` to `Full` (ConsoleObject.rs:1176).
         let colors = bun_core::Output::enable_ansi_colors_stderr();

test/js/bun/util/inspect-error-cycle.test.ts

@@ -0,0 +1,189 @@
+// Error-graph cycle / deep-chain segfaults in the native error printer.
+// The AggregateError `errors` recursion had no stack check and no visited
+// set, so self/mutual cycles and very deep nesting hit the stack guard page
+// (silent SIGSEGV) via `print_errorlike_object` -> `for_each` -> `agg_iter`.
+import { describe, expect, test } from "bun:test";
+import { bunEnv, bunExe } from "harness";
+
+type Shape = { name: string; build: string };
+type Sink = { name: string; wrap: (b: string) => string; allowFail: boolean };
+
+const shapes: Shape[] = [
+  {
+    name: "self-cycle",
+    build: `const ae = new AggregateError([], "self"); ae.errors = [ae]; const e = ae;`,
+  },
+  {
+    name: "mutual-cycle",
+    build: `const a = new AggregateError([], "A"); const b = new AggregateError([], "B"); a.errors = [b]; b.errors = [a]; const e = a;`,
+  },
+  {
+    name: "deleted-errors",
+    build: `const ae = new AggregateError([new Error("x")], "del"); delete ae.errors; const e = ae;`,
+  },
+  {
+    name: "accessor-errors",
+    build: `const ae = new AggregateError([], "acc"); Object.defineProperty(ae, "errors", { get() { throw new Error("boom"); } }); const e = ae;`,
+  },
+  {
+    name: "non-iterable-errors",
+    build: `const ae = new AggregateError([], "ni"); ae.errors = 42; const e = ae;`,
+  },
+  {
+    name: "mixed-agg-cause",
+    build: `const a = new AggregateError([], "A"); const c = new Error("C"); a.errors = [c]; c.cause = a; const e = a;`,
+  },
+];
+
+const sinks: Sink[] = [
+  { name: "console.log", wrap: b => `${b} console.log(e);`, allowFail: false },
+  { name: "console.error", wrap: b => `${b} console.error(e);`, allowFail: false },
+  { name: "Bun.inspect", wrap: b => `${b} Bun.inspect(e);`, allowFail: false },
+  { name: "uncaught-throw", wrap: b => `${b} throw e;`, allowFail: true },
+  {
+    name: "unhandled-reject",
+    wrap: b => `${b} Promise.reject(e); await 1;`,
+    allowFail: true,
+  },
+  {
+    name: "uncaughtException-handler",
+    wrap: b => `process.on("uncaughtException", err => { console.error(err); process.exit(0); }); ${b} throw e;`,
+    allowFail: false,
+  },
+];
+
+describe.concurrent("error-graph cycles do not crash the printer", () => {
+  for (const shape of shapes) {
+    for (const sink of sinks) {
+      const cell = `${shape.name} x ${sink.name}`;
+      test(cell, async () => {
+        const code = sink.wrap(shape.build);
+        await using proc = Bun.spawn({
+          cmd: [bunExe(), "--no-install", "-e", code],
+          env: bunEnv,
+          stdout: "pipe",
+          stderr: "pipe",
+        });
+        const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+        if (proc.signalCode) {
+          throw new Error(
+            `crashed with ${proc.signalCode}\nstdout: ${stdout.slice(0, 300)}\nstderr: ${stderr.slice(0, 300)}`,
+          );
+        }
+        if (sink.allowFail) {
+          expect(exitCode).toBeLessThan(128);
+        } else {
+          if (exitCode !== 0) {
+            throw new Error(`exit ${exitCode}\nstdout: ${stdout.slice(0, 300)}\nstderr: ${stderr.slice(0, 300)}`);
+          }
+          expect(exitCode).toBe(0);
+        }
+      });
+    }
+  }
+});
+
+// Depth tests kept out of the concurrent matrix: each prints hundreds of
+// headers before the stack guard fires, which is seconds under debug+ASAN.
+// Release bun segfaults at ~2000 levels.
+describe("error-graph depth does not crash the printer", () => {
+  const deepAgg = `let x = new AggregateError([], "leaf"); for (let i = 0; i < 3000; i++) x = new AggregateError([x], "n" + i); const e = x;`;
+  const deepCause = `let x = new Error("leaf"); for (let i = 0; i < 3000; i++) x = new Error("n" + i, { cause: x }); const e = x;`;
+
+  for (const sink of sinks) {
+    test(`deep-aggregate x ${sink.name}`, async () => {
+      await using proc = Bun.spawn({
+        cmd: [bunExe(), "--no-install", "-e", sink.wrap(deepAgg)],
+        env: bunEnv,
+        stdout: "pipe",
+        stderr: "pipe",
+      });
+      const [, , exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+      expect(proc.signalCode).toBeFalsy();
+      if (sink.allowFail) expect(exitCode).toBeLessThan(128);
+      else expect(exitCode).toBe(0);
+    });
+  }
+
+  // The cause-chain depth guard exists but was inert on the uncaught /
+  // rejection path because the formatter's stack_check was never seated.
+  for (const sink of sinks.filter(s => s.allowFail)) {
+    test(`deep-cause x ${sink.name}`, async () => {
+      await using proc = Bun.spawn({
+        cmd: [bunExe(), "--no-install", "-e", sink.wrap(deepCause)],
+        env: bunEnv,
+        stdout: "pipe",
+        stderr: "pipe",
+      });
+      const [, , exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+      expect(proc.signalCode).toBeFalsy();
+      expect(exitCode).toBeLessThan(128);
+    });
+  }
+});
+
+describe.concurrent("AggregateError printer output", () => {
+  test("self-cycle renders [Circular] and includes the header", async () => {
+    await using proc = Bun.spawn({
+      cmd: [
+        bunExe(),
+        "-e",
+        `const ae = new AggregateError([], "outer"); ae.errors = [ae]; process.stdout.write(Bun.inspect(ae));`,
+      ],
+      env: { ...bunEnv, NO_COLOR: "1" },
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+    expect(stderr).toBe("");
+    expect(stdout).toContain("[Circular]");
+    expect(stdout).toContain("outer");
+    expect(exitCode).toBe(0);
+  });
+
+  test("deep nesting renders depth marker", async () => {
+    await using proc = Bun.spawn({
+      cmd: [
+        bunExe(),
+        "-e",
+        `let x = new AggregateError([], "leaf"); for (let i = 0; i < 3000; i++) x = new AggregateError([x], ""); process.stdout.write(Bun.inspect(x));`,
+      ],
+      env: { ...bunEnv, NO_COLOR: "1" },
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [stdout, , exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+    expect(stdout).toContain("[AggregateError: nesting too deep]");
+    expect(exitCode).toBe(0);
+  });
+
+  test("uncaught AggregateError prints its own message", async () => {
+    await using proc = Bun.spawn({
+      cmd: [bunExe(), "-e", `throw new AggregateError([new Error("inner")], "outer message");`],
+      env: { ...bunEnv, NO_COLOR: "1" },
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+    expect(stderr).toContain("outer message");
+    expect(stderr).toContain("inner");
+    expect(exitCode).toBe(1);
+  });
+
+  test("deleted errors property prints header", async () => {
+    await using proc = Bun.spawn({
+      cmd: [
+        bunExe(),
+        "-e",
+        `const ae = new AggregateError([new Error("x")], "msg"); delete ae.errors; process.stdout.write(Bun.inspect(ae));`,
+      ],
+      env: { ...bunEnv, NO_COLOR: "1" },
+      stdout: "pipe",
+      stderr: "pipe",
+    });
+    const [stdout, stderr, exitCode] = await Promise.all([proc.stdout.text(), proc.stderr.text(), proc.exited]);
+    expect(stderr).toBe("");
+    expect(stdout).toContain("msg");
+    expect(exitCode).toBe(0);
+  });
+});