Kernel Panic (instruction exception) in com.apple.nke.ppp on Apple Silicon (M-series)

[m-hajiabadi]

Frequent Kernel Panics occur during active SSTP sessions on macOS Sequoia (Darwin 24.6.0). The crash is tied to the com.apple.nke.ppp extension, typically after 30–60 minutes of stable connectivity.

Environment:

• OS: macOS 15.x (Build 24G231)
• Hardware: Apple Silicon (ARM64)
• Client: sstp-client via Homebrew

Panic Signature:

panic(cpu 3 caller 0xfffffe00182b947c): Break 0x5519 instruction exception from kernel.
Panic (by design) at pc 0xfffffe0017fa89c4
Kernel Extensions in backtrace: com.apple.nke.ppp(1.9)

Context & Steps to Reproduce:

1. Connect using sstpc with standard flags.
2. Route traffic via ppp0 using split tunneling (0/1 and 128/1).
3. The system crashes randomly during data transfer or LCP keep-alive intervals.
4. Note: The "Instruction Exception" suggests a race condition or memory misalignment between sstpc userspace handling and the macOS PPP kernel stack on ARM64.

Proposed Diagnostics:

• Potential MTU/MRU fragmentation triggering the NKE crash.
• Possible race condition during LCP Echo requests.

crash_log.rtf