iOS 11 EXC_BAD_ACCESS KERN_INVALID_ADDRESS on dealloc

Question

Can't replicate a crash on iOS 11 devices when deallocating the DetailViewController.

The app has a DetailViewController which inherits from the BaseViewController. DetailViewController has a DetailViewModel property.

DetailViewController, BaseViewController and DetailViewModel are all written in Objective-C. I upgraded the Swift version to Swift 4 and added a Swift Extension to DetailViewModel.

@objc extension DetailViewModel {
        func foo() {
            let conclusionBlock: (() -> Void) = { [weak self] in
                guard let strongSelf = self else { return }
                strongSelf.viewController.reloadData()
            }
            let viewModel = OtherViewModel(conclusionBlock: conclusionBlock)
            let otherViewController = OtherViewController.make(viewModel: viewModel)

            let nav = UINavigationController(rootViewController: otherViewController)
            nav.modalPresentationStyle = .fullScreen

            viewController.present(nav, animated: true, completion: nil)
        }
    }

Looking at the logs, func foo() in the DetailViewModel swift extension is not called and it's still crashing on dealloc.

Has anyone got ideas as to what's the issue or how to fix it?

Thank you

stack trace:

Crashed: com.apple.main-thread
0  libobjc.A.dylib                0x18589d7f4 objc_object::release() + 16
1  CoreFoundation                 0x1862f3108 cow_cleanup + 112
2  CoreFoundation                 0x18623a51c -[__NSArrayM dealloc] + 68
3  libobjc.A.dylib                0x18587eef4 object_cxxDestructFromClass(objc_object*, objc_class*) + 148
4  libobjc.A.dylib                0x18588c638 objc_destructInstance + 88
5  libobjc.A.dylib                0x18588c690 object_dispose + 16
6  AppName                        0x100c7dbec -[DetailViewModel .cxx_destruct] (DetailViewModel.m:43)
7  libobjc.A.dylib                0x18587eef4 object_cxxDestructFromClass(objc_object*, objc_class*) + 148
8  libobjc.A.dylib                0x18588c638 objc_destructInstance + 88
9  libobjc.A.dylib                0x18588c690 object_dispose + 16
10 AppName                        0x100cbe358 -[DetailViewController .cxx_destruct] (DetailViewController.m:103)
11 libobjc.A.dylib                0x18587eef4 object_cxxDestructFromClass(objc_object*, objc_class*) + 148
12 libobjc.A.dylib                0x18588c638 objc_destructInstance + 88
13 libobjc.A.dylib                0x18588c690 object_dispose + 16
14 UIKit                          0x18fb338f4 -[UIResponder dealloc] + 156
15 UIKit                          0x18f8e9e7c -[UIViewController dealloc] + 1776
16 AppName                        0x100c9b66c -[BaseViewController dealloc] (BaseViewController.m:56)
17 AppName                        0x100cb6570 -[DetailViewController dealloc] (DetailViewController.m:261)
18 UIKit                          0x18f9d3ec4 __destroy_helper_block_.150 + 80
19 libsystem_blocks.dylib         0x185d91a60 _Block_release + 160
20 UIKit                          0x18fa5f5bc -[UIViewAnimationBlockDelegate .cxx_destruct] + 72
21 libobjc.A.dylib                0x18587eef4 object_cxxDestructFromClass(objc_object*, objc_class*) + 148
22 libobjc.A.dylib                0x18588c638 objc_destructInstance + 88
23 libobjc.A.dylib                0x18588c690 object_dispose + 16
24 CoreFoundation                 0x18623d998 -[__NSDictionaryI dealloc] + 136
25 libobjc.A.dylib                0x18589e138 (anonymous namespace)::AutoreleasePoolPage::pop(void*) + 836
26 CoreFoundation                 0x186232050 _CFAutoreleasePoolPop + 28
27 CoreFoundation                 0x186311b04 __CFRunLoopRun + 2020
28 CoreFoundation                 0x1862322d8 CFRunLoopRunSpecific + 436
29 GraphicsServices               0x1880c3f84 GSEventRunModal + 100
30 UIKit                          0x18f7df880 UIApplicationMain + 208
31 AppName                        0x100d59540 main (main.m:10)
32 libdyld.dylib                  0x185d5656c start + 4 

Answer 1

To help with replicating the issue, try turning on Address Sanitizer in Xcode 9.