Crash: Double-free in AnimationContext when removing animations (Core Animation engine)

[ed-huang-jp]

Summary

App crashes with ___BUG_IN_CLIENT_OF_LIBMALLOC_POINTER_BEING_FREED_WAS_NOT_ALLOCATED when AnimationContext is deallocated. This occurs due to a race condition between Swift ARC and Core Animation's memory management when removing animations.

Crash Stack Trace

Crashed: com.apple.main-thread

0  libsystem_kernel.dylib         0xb1dc __pthread_kill + 8
1  libsystem_pthread.dylib        0x7c60 pthread_kill + 268
2  libsystem_c.dylib              0x770ac abort + 124
3  libsystem_malloc.dylib         0x16d70 malloc_vreport + 892
4  libsystem_malloc.dylib         0x169e8 malloc_report + 64
5  libsystem_malloc.dylib         0x11594 ___BUG_IN_CLIENT_OF_LIBMALLOC_POINTER_BEING_FREED_WAS_NOT_ALLOCATED + 32
6  libswiftCore.dylib             0x39978c _swift_release_dealloc + 56
7  libswiftCore.dylib             0x39a700 bool swift::RefCounts<swift::RefCountBitsT<(swift::RefCountInlinedness)1>>::doDecrementSlow<(swift::PerformDeinit)1>(swift::RefCountBitsT<(swift::RefCountInlinedness)1>, unsigned int) + 152
8  App                            0x241498 destroy for AnimationContext + 4338406552