After the official release of iOS 18.3, our app has collected numerous identical crash logs. These crashes occurred on different devices, but the common denominator is that they all, and only, happened on iOS 18.3. Based on the stack trace, the crash is happening internally within WebKit. The details are as follows:
Crashed: com.apple.main-thread 0 WebCore 0x721f9c <redacted> + 28 1 WebCore 0x15b6924 <redacted> + 11356 2 WebCore 0x15b174c <redacted> + 1008 3 WebCore 0x1776e4 <redacted> + 292 4 WebCore 0x17753c WebCore::SerializedScriptValue::deserialize(OpaqueJSContext const*, OpaqueJSValue const**) + 100 5 WebKit 0x530b28 <redacted> + 92 6 WebKit 0x5a0d2c <redacted> + 176 7 WebKit 0x9e74b0 <redacted> + 956 8 WebKit 0xe43d58 <redacted> + 392 9 WebKit 0x886ac <redacted> + 272 10 WebKit 0x88940 <redacted> + 44 11 WebKit 0x87a74 <redacted> + 252 12 WebKit 0x875ec <redacted> + 576 13 JavaScriptCore 0x2f8a48 ***::RunLoop::performWork() + 204 14 JavaScriptCore 0x2f895c ***::RunLoop::performWork(void*) + 36 15 CoreFoundation 0x73f4c CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION + 28 16 CoreFoundation 0x73ee0 __CFRunLoopDoSource0 + 176 17 CoreFoundation 0x76b40 __CFRunLoopDoSources0 + 244 18 CoreFoundation 0x75d3c __CFRunLoopRun + 840 19 CoreFoundation 0xc8284 CFRunLoopRunSpecific + 588 20 GraphicsServices 0x14c0 GSEventRunModal + 164 21 UIKitCore 0x3ee674 -[UIApplication _run] + 816 22 UIKitCore 0x14e88 UIApplicationMain + 340 23 18Birdies 0x1b2d3c main + 14 (main.m:14) 24 ??? 0x1ac161de8 (Missing)