cherry-pick-70579363ce7b.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Reilly Grant <reillyg@chromium.org>
Date: Wed, 22 Jul 2020 04:00:16 +0000
Subject: usb: Prevent iterator invalidation during Promise resolution

This change swaps sets of ScriptPromiseResolvers into local variables in
a number of places where it was possible for script to execute during
the call to Resolve() or Reject() and modify the set being iterated
over, thus invalidating the iterator.

(cherry picked from commit dbc6c3c3652680e287c60b3c6551622748543439)

Bug: 1106773
Change-Id: Id4eb0cd444a7dbb5de23038ec80f44fee649cfe4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2304538
Auto-Submit: Reilly Grant <reillyg@chromium.org>
Commit-Queue: James Hollyer <jameshollyer@chromium.org>
Reviewed-by: James Hollyer <jameshollyer@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#790217}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2310964
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/branch-heads/4183@{#842}
Cr-Branched-From: 740e9e8a40505392ba5c8e022a8024b3d018ca65-refs/heads/master@{#782793}

diff --git a/third_party/blink/renderer/modules/webusb/usb.cc b/third_party/blink/renderer/modules/webusb/usb.cc
index cbe336ae6991d42aa7082aa99a95c4a380aa790f..ce38760e569e03bef1f64b14fca1122d7f98b452 100644
--- a/third_party/blink/renderer/modules/webusb/usb.cc
+++ b/third_party/blink/renderer/modules/webusb/usb.cc
@@ -264,15 +264,22 @@ void USB::OnDeviceRemoved(UsbDeviceInfoPtr device_info) {
 void USB::OnServiceConnectionError() {
   service_.reset();
   client_receiver_.reset();
-  for (ScriptPromiseResolver* resolver : get_devices_requests_)
+
+  // Move the set to a local variable to prevent script execution in Resolve()
+  // from invalidating the iterator used by the loop.
+  HeapHashSet<Member<ScriptPromiseResolver>> get_devices_requests;
+  get_devices_requests.swap(get_devices_requests_);
+  for (auto& resolver : get_devices_requests)
     resolver->Resolve(HeapVector<Member<USBDevice>>(0));
-  get_devices_requests_.clear();
 
-  for (ScriptPromiseResolver* resolver : get_permission_requests_) {
+  // Move the set to a local variable to prevent script execution in Reject()
+  // from invalidating the iterator used by the loop.
+  HeapHashSet<Member<ScriptPromiseResolver>> get_permission_requests;
+  get_permission_requests.swap(get_permission_requests_);
+  for (auto& resolver : get_permission_requests) {
     resolver->Reject(MakeGarbageCollected<DOMException>(
         DOMExceptionCode::kNotFoundError, kNoDeviceSelected));
   }
-  get_permission_requests_.clear();
 }
 
 void USB::AddedEventListener(const AtomicString& event_type,
diff --git a/third_party/blink/renderer/modules/webusb/usb_device.cc b/third_party/blink/renderer/modules/webusb/usb_device.cc
index da7d3003c3a38cdf650ec0ab5c131fecd80ee4e5..23856abc9a59770f816c6d18cd12602e6d0dae58 100644
--- a/third_party/blink/renderer/modules/webusb/usb_device.cc
+++ b/third_party/blink/renderer/modules/webusb/usb_device.cc
@@ -1099,11 +1099,15 @@ void USBDevice::AsyncReset(ScriptPromiseResolver* resolver, bool success) {
 void USBDevice::OnConnectionError() {
   device_.reset();
   opened_ = false;
-  for (ScriptPromiseResolver* resolver : device_requests_) {
+
+  // Move the set to a local variable to prevent script execution in Reject()
+  // from invalidating the iterator used by the loop.
+  HeapHashSet<Member<ScriptPromiseResolver>> device_requests;
+  device_requests.swap(device_requests_);
+  for (auto& resolver : device_requests) {
     resolver->Reject(MakeGarbageCollected<DOMException>(
         DOMExceptionCode::kNotFoundError, kDeviceDisconnected));
   }
-  device_requests_.clear();
 }
 
 bool USBDevice::MarkRequestComplete(ScriptPromiseResolver* resolver) {