[iOS] Crash EXC_BAD_ACCESS (KERN_INVALID_ADDRESS) on webview unmounting

[Minishlink]

Bug description:

Hello, we have these crash reports on Crashlytics after an upgrade from 11.23.1 to 13.2.1

EXC_BAD_ACCESS (KERN_INVALID_ADDRESS) 0x000000000000001e
Crashed: com.apple.main-thread
0  libobjc.A.dylib                0x9af0 object_isClass + 16
1  Foundation                     0x8090 KVO_IS_RETAINING_ALL_OBSERVERS_OF_THIS_OBJECT_IF_IT_CRASHES_AN_OBSERVER_WAS_OVERRELEASED_OR_SMASHED + 72
2  Foundation                     0x3f9f8 NSKeyValueWillChangeWithPerThreadPendingNotifications + 296
3  WebKit                         0x430b6c WebKit::PageClientImplCocoa::gpuProcessDidExit() + 44
4  WebKit                         0x658748 WebKit::WebProcessPool::gpuProcessExited(int, WebKit::ProcessTerminationReason) + 488
5  WebKit                         0x6e4f54 WebKit::GPUProcessProxy::gpuProcessExited(WebKit::ProcessTerminationReason) + 216
6  WebKit                         0x6e50cc WebKit::GPUProcessProxy::processIsReadyToExit() + 136
7  WebKit                         0x1d6e98 WebKit::GPUProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 200
8  WebKit                         0x415f10 IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 260
9  WebKit                         0x418c1c WTF::Detail::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_13, void>::call() + 188
10 JavaScriptCore                 0x51b58 WTF::RunLoop::performWork() + 200
11 JavaScriptCore                 0x52890 WTF::RunLoop::performWork(void*) + 36
12 CoreFoundation                 0xd5f54 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
13 CoreFoundation                 0xe232c __CFRunLoopDoSource0 + 176
14 CoreFoundation                 0x66210 __CFRunLoopDoSources0 + 244
15 CoreFoundation                 0x7bba8 __CFRunLoopRun + 836
16 CoreFoundation                 0x80ed4 CFRunLoopRunSpecific + 612
17 GraphicsServices               0x1368 GSEventRunModal + 164
18 UIKitCore                      0x3a23d0 -[UIApplication _run] + 888
19 UIKitCore                      0x3a2034 UIApplicationMain + 340
20 app                            0x679c main + 8 (main.m:8)
21 ???                            0x1a5fec960 (Manquant)

EXC_BAD_ACCESS (KERN_INVALID_ADDRESS) 0x0000000000000000
Crashed: com.apple.main-thread
0  libobjc.A.dylib                0x7d44 class_getMethodImplementation + 64
1  Foundation                     0xa35c0 _NSKVONotifyingOriginalClassForIsa + 32
2  Foundation                     0xaaf8 _NSKeyValueObservationInfoGetObservances + 264
3  Foundation                     0x3f6d8 NSKeyValueWillChangeWithPerThreadPendingNotifications + 232
4  WebKit                         0x432fe0 WebKit::PageClientImplCocoa::gpuProcessDidExit() + 44
5  WebKit                         0x65d628 WebKit::WebProcessPool::gpuProcessExited(int, WebKit::ProcessTerminationReason) + 488
6  WebKit                         0x6ea804 WebKit::GPUProcessProxy::gpuProcessExited(WebKit::ProcessTerminationReason) + 216
7  WebKit                         0x6ea97c WebKit::GPUProcessProxy::processIsReadyToExit() + 136
8  WebKit                         0x1d8178 WebKit::GPUProcessProxy::didReceiveMessage(IPC::Connection&, IPC::Decoder&) + 200
9  WebKit                         0x41835c IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 260
10 WebKit                         0x41b068 WTF::Detail::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_13, void>::call() + 188
11 JavaScriptCore                 0x520b0 WTF::RunLoop::performWork() + 200
12 JavaScriptCore                 0x52de8 WTF::RunLoop::performWork(void*) + 36
13 CoreFoundation                 0xd5f24 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
14 CoreFoundation                 0xe22fc __CFRunLoopDoSource0 + 176
15 CoreFoundation                 0x661c0 __CFRunLoopDoSources0 + 244
16 CoreFoundation                 0x7bb7c __CFRunLoopRun + 836
17 CoreFoundation                 0x80eb0 CFRunLoopRunSpecific + 612
18 GraphicsServices               0x1368 GSEventRunModal + 164
19 UIKitCore                      0x3a1668 -[UIApplication _run] + 888
20 UIKitCore                      0x3a12cc UIApplicationMain + 340
21 app                            0x679c main + 8 (main.m:8)
22 ???                            0x1e3b64960 (Manquant)

To Reproduce:

Unfortunately I could not reproduce this. It seems to happen only on iOS 16 although it might just be because of our userbase and the relative rarity of the crash (2% partial rollout of the update).
The logs indicate that the crash happens after a screen unmounts, where there was an html5 video playing via react-native-webview.

Environment:

• OS: iOS
• OS version: iOS 16
• react-native version: 0.71.11
• react-native-webview version: 13.2.1

[Minishlink]

10% rollout and still only iOS 16

This could come from an observer not correctly deallocated ?

Maybe the memory leak from #2930
If not one of #2535 #2686

I'll send an update with #2930 reverted and will keep you updated

[francesco-cerio]

Hi, I'm having the same crash.
Any update on this?

[Minishlink]

I reverted #2930 and deployed an update of our app, it is at 2% partial rollout and so far no crash. On Thursday (10% rollout), I will confirm this. (EDIT on Thursday : confirmed)

diff --git a/node_modules/react-native-webview/apple/RNCWebViewImpl.m b/node_modules/react-native-webview/apple/RNCWebViewImpl.m
index ffcf4b2..6b5a8de 100644
--- a/node_modules/react-native-webview/apple/RNCWebViewImpl.m
+++ b/node_modules/react-native-webview/apple/RNCWebViewImpl.m
@@ -436,16 +436,9 @@ - (WKWebViewConfiguration *)setUpWkWebViewConfig
   return wkWebViewConfig;
 }
 
-// react-native-mac os does not support didMoveToSuperView https://github.com/microsoft/react-native-macos/blob/main/React/Base/RCTUIKit.h#L388
-#if !TARGET_OS_OSX
-- (void)didMoveToSuperview
-{
-  if (_webView == nil) {
-#else
 - (void)didMoveToWindow
 {
   if (self.window != nil && _webView == nil) {
-#endif // !TARGET_OS_OSX
     WKWebViewConfiguration *wkWebViewConfig = [self setUpWkWebViewConfig];
     _webView = [[RNCWKWebView alloc] initWithFrame:self.bounds configuration: wkWebViewConfig];
     [self setBackgroundColor: _savedBackgroundColor];

[minotogna]

I reverted #2930 and deployed an update of our app, it is at 2% partial rollout and so far no crash. On Thursday (10% rollout), I will confirm this.

diff --git a/node_modules/react-native-webview/apple/RNCWebViewImpl.m b/node_modules/react-native-webview/apple/RNCWebViewImpl.m
index ffcf4b2..6b5a8de 100644
--- a/node_modules/react-native-webview/apple/RNCWebViewImpl.m
+++ b/node_modules/react-native-webview/apple/RNCWebViewImpl.m
@@ -436,16 +436,9 @@ - (WKWebViewConfiguration *)setUpWkWebViewConfig
   return wkWebViewConfig;
 }
 
-// react-native-mac os does not support didMoveToSuperView https://github.com/microsoft/react-native-macos/blob/main/React/Base/RCTUIKit.h#L388
-#if !TARGET_OS_OSX
-- (void)didMoveToSuperview
-{
-  if (_webView == nil) {
-#else
 - (void)didMoveToWindow
 {
   if (self.window != nil && _webView == nil) {
-#endif // !TARGET_OS_OSX
     WKWebViewConfiguration *wkWebViewConfig = [self setUpWkWebViewConfig];
     _webView = [[RNCWKWebView alloc] initWithFrame:self.bounds configuration: wkWebViewConfig];
     [self setBackgroundColor: _savedBackgroundColor];

@Minishlink that pr I guess fixed another bug... is it safe to revert it?

[Minishlink]

Basically, before this PR, ios webviews were rendered only when the current windows was completely focused, and not during focus. Eg. on a tab view, it was not visible while swiping the tab. If you need this behavior and it is more important that the crashes then yes, don't revert it.

[minotogna]

Basically, before this PR, ios webviews were rendered only when the current windows was completely focused, and not during focus. Eg. on a tab view, it was not visible while swiping the tab. If you need this behavior and it is more important that the crashes then yes, don't revert it.

@Minishlink got it. thank you. I don't need that behaviour . we'll try to revert to version 12.4.0 waiting for the official fix.

[ororsatti]

It might be related to the memory leak RNWW
introduced on 13.0.0 .
#3020

[Minishlink]

#2930 has been reverted in #3041, issue is fixed