- Track whether transferred thread's original context was successfully restored.
- In the catch block, leak the remote allocation instead of freeing it if the thread was not restored; this prevents the target process from executing freed memory.
- Remove redundant 'op == 0x55' check in InstructionAnalyzer (already matched by (op & 0xF8) == 0x50).
- Simplify MemoryBase ReadString align-down expression to previousLen - (previousLen % nullLen).
- Change StubAllocator size parameter from nint to int for clarity (internal test seam).
Tests: 199 passing, 4 integration/interactive skipped.
A non-faulting probe payload returns (rsp+8)&15 from the callee, which is 0
only when the stub delivers callee entry rsp ≡ 8 (mod 16) per the Microsoft
x64 ABI. Proves the stub frame alignment end-to-end through CreateRemoteThread
without risking a #GP that would crash the in-process test host. Verified to
fail against the old fixed-0x20 frame.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
- Add RemoteAllocator / RemoteReleaser internal test seams for string/struct scratch memory.
- Route all scratch allocation/freeing through the seams so tests can observe leaks.
- Fix inverted StubAllocator ownership: a caller-provided stub is now never freed by the executor.
- Rewrite Execute_releases_allocated_remote_memory_on_write_failure to fail pre-fix by tracking fake allocations through the seams.
- Update WriteFailingMemoryBase to carry a valid self-handle so the executor reaches the marshal/write path.
Tests: 198 passing, 4 integration/interactive skipped.
- MainThreadDispatcher: guard DispatchHook with try/catch so exceptions never escape to native caller; drain and fault pending work on Dispose; synchronize Execute/ExecuteAsync/Dispose against race/dispose.
- InstructionAnalyzer: require ModRM 0xEC for 0x83/0x81 sub-esp/rsp forms, rejecting unsafe RIP-relative or memory forms.
- PatternScannerCache: implement value equality on CacheKey so repeated scans actually hit cache.
- BackgroundTaskExecutor: add remote allocations to the free list immediately after VirtualAllocEx, before any write that could fail and leak.
- redirect: capture and restore original page protection in Apply/Remove instead of leaving target RWX.
- Regression tests for all six fixes.
Tests: 198 passing, 4 integration/interactive skipped.
The x64 frame math (0x20 + 8*stackArgs) and x86 arg buffer size grow with the
argument count. An absurdly large count could overflow int and produce a bogus
or negative frame. Add a MaxArguments (256) bound checked at the public entry —
far above any real calling convention — so the arithmetic stays in range. Add a
test asserting the cap is inclusive and count+1 throws.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
x64 call stub was ABI-broken: fixed 0x20 frame left rsp misaligned at the
inner call (callee entry rsp ≡ 0, ABI requires ≡ 8) and, for 5+ args, wrote
stack args over the return address. Compute frame K ≡ 8 (mod 16), K ≥
0x20 + 8*stackArgs, so the callee sees a 16-aligned stack and stack args land
above the shadow window. Load register args as full 64-bit imm64 (was imm32,
which truncated pointers > 4 GiB). BuildCallStub now takes nuint[]; x86 range-
checks each arg against uint.MaxValue instead of silently truncating.
MarshalCache conflated managed and unmanaged width in one Size field: the
blittable path needs Unsafe.SizeOf<T> (bool = 1) while the marshal path needs
Marshal.SizeOf<T> (inline ByValTStr/ByValArray expand past the managed
pointer). Add MarshalSize; MemoryBase picks per TypeRequiresMarshal at all four
IO sites. Prevents PtrToStructure/StructureToPtr from over-reading/overwriting
the pinned scratch buffer (heap corruption on write).
Extract shared RPM/WPM into RpmHelper: honor partial reads (dead Array.Resize
removed), consistent write-return semantics; InProcessReader now guards
MainModule like ExternalReader.
Tests: x64 frame-alignment property + inline-marshal round-trip added (both
fail against the pre-fix code); existing x64 byte-expectation tests updated to
the new frame. Build clean, 100/100 pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
kbe
