iOS 16.0 _cache_getImp crash due to bad access

Question

Created Sep ’22

Replies 3

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Participants 5

After the user upgrades to iOS16, our app receives a few crash reports attempted to dereference garbage pointer on iOS16.

These issues only happen on iOS16. Here we provide some typical cases. It may be a system bug!

Case A

0	libobjc.A.dylib	_cache_getImp
1	libobjc.A.dylib	_class_respondsToSelector_inst
2	Foundation	__NSDescriptionWithStringProxyFunc
3	CoreFoundation	___CFStringAppendFormatCore
4	CoreFoundation	__CFStringCreateWithFormatAndArgumentsReturningMetadata
5	CoreFoundation	__CFStringCreateWithFormatAndArgumentsAux2
6	Foundation	+[NSString stringWithFormat:]

Case B

0	libobjc.A.dylib	_cache_getImp
1	libobjc.A.dylib	_object_getMethodImplementation
2	CoreFoundation	__NSIsNSString
3	CoreFoundation	-[NSTaggedPointerString isEqual:]
4	CoreFoundation	-[__NSDictionaryM objectForKey:]

Boost

Answer 1

MobileTen OP

Sep ’22

Something like this will only happen if an object is dereferenced during access. So some root cause analysis based on what is actually calling these APIs from user/developer code is a good place to start.

0

Answer 2

DTS Engineer OP

Apple

Sep ’22

What MobileTen said plus…

Problems like this are often caused by memory managements bugs. I recommend that you apply the standard memory debugging tools.

Also, can you post a full crash report? See Posting a Crash Report for advice on how to do that.

Share and Enjoy
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

0

Answer 3

linziyi127 OP

May ’23

We are having the same problem too. Only on iOS16. Has this problem been resolved? is it related to the Hook of NSString？

0