Crash observed on brought app to foreground with exit reason (namespace: 3 code: 0x2) - OS_REASON_CODESIGNING

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neha24 OP

Created Jun ’25

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Crash observed on brought app to foreground with exit reason (namespace: 3 code: 0x2) - OS_REASON_CODESIGNING

App was being idle and then the user brought an application to foreground, on being app transition observed app crash.

2025-04-23 19:16:26.795985 +0530 launchd exited with exit reason (namespace: 3 code: 0x2) - OS_REASON_CODESIGNING, ran for 1801880ms default

Exception Type: EXC_BAD_ACCESS (SIGKILL) Exception Subtype: KERN_PROTECTION_FAILURE at 0x0000006d6f632e74 Exception Codes: 0x0000000000000002, 0x0000006d6f632e74 VM Region Info: 0x6d6f632e74 is in 0x1000000000-0x7000000000; bytes after start: 401300729460 bytes before end: 11016130955 REGION TYPE START - END [ VSIZE] PRT/MAX SHRMOD REGION DETAIL commpage (reserved) fc0000000-1000000000 [ 1.0G] ---/--- SM=NUL reserved VM address space (unallocated) ---> GPU Carveout (reserved) 1000000000-7000000000 [384.0G] ---/--- SM=NUL reserved VM address space (unallocated) UNUSED SPACE AT END Termination Reason: CODESIGNING 2 Invalid Page

Attached the crash stack file and sysdiagnose file here https://feedbackassistant.apple.com/feedback/17723296

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Answer 1

Frameworks Engineer OP

Apple

Jun ’25

Accepted Answer

Fortunately this crash does not appear related to a code signing issue.

Execution of Thread 6 branched to an address which just so happened to reside within the GPU Carveout memory region. The GPU Carveout memory region does not contain executable code, nor do those pages have an associated code signature. Hence the "CODESIGNING" termination reason. But it is better to think of this crash as a segmentation fault (EXC_BAD_ACCESS / SIGSEGV).

Exception Type:    EXC_BAD_ACCESS (SIGKILL)
Exception Subtype: KERN_PROTECTION_FAILURE at 0x0000006d6f632e74
Exception Codes:   0x0000000000000002, 0x0000006d6f632e74

VM Region Info: 0x6d6f632e74 is in 0x1000000000-0x7000000000;  bytes after start: 401300729460  bytes before end: 11016130955
      REGION TYPE                 START - END      [ VSIZE] PRT/MAX SHRMOD  REGION DETAIL
      commpage (reserved)      fc0000000-1000000000 [  1.0G] ---/--- SM=NUL  reserved VM address space (unallocated)
--->  GPU Carveout (reserved) 1000000000-7000000000 [384.0G] ---/--- SM=NUL  reserved VM address space (unallocated)
      UNUSED SPACE AT END

The kn_plt_worker_thread_handle_events function in thread 6 loaded a pointer from memory that had either already been free'd or had been overwritten with bad data, and attempted to invoke the 'function' at that address.

Check out the Investigating memory access crashes article for tips investigating this kind crash.

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