RE-UE4SS Linux v0.1.1

RE-UE4SS Linux v0.1.1

This patch prerelease hardens the native Linux launcher and updates the
validated Palworld Dedicated Server target.

Validated target

• Palworld Dedicated Server 1.0.2.100933
• Steam build ID 24370498
• Unreal Engine 5.1.1
• Native x86-64 Linux server
• Fedora Linux 43 validation hosts
• PalServer SHA-256
  d16b4d840a30dc3f467fe1059a0088ddb08a4b513cc45150767cba1785867d30
• PalServer ELF build ID c339de6590a6a669
• Scoped SELinux entrypoint type palworld_ue4ss_exec_t
• Scoped SELinux process domain palworld_ue4ss_t

The exact release source commit, packaged loader identity, archive checksums,
and final acceptance evidence are recorded in the release manifest and package
metadata.

Highlights

• Detect stale SELinux labels on the host executable before UE4SS startup.
• Add UE4SS_SELINUX_PREFLIGHT modes:
  • off
  • warn, which is the default
  • strict
• Add UE4SS_EXPECTED_SELINUX_TYPE for scoped SELinux deployments.
• Exit with status 8 in strict mode when the host executable has an unexpected
  SELinux type.
• Warn when common unsuitable default types such as user_home_t are detected.
• Document persistent semanage fcontext mappings.
• Document running restorecon after game updates and validation operations.
• Continue operating without enabling the global execheap boolean.
• Update the current compatibility target to Palworld 1.0.2.100933.

Incident resolved

The Palworld 1.0.2 update replaced PalServer-Linux-Shipping with a new inode.
The replacement received the default user_home_t SELinux type instead of the
persistent UE4SS entrypoint type.

The server consequently remained in unconfined_t, and SELinux denied
execheap when PolyHook attempted to make an EngineTick trampoline executable.
The server later faulted when execution entered the non-executable trampoline.

Restoring palworld_ue4ss_exec_t caused the expected transition into
palworld_ue4ss_t. The existing loader then started successfully with no new
SELinux AVCs.

No PatternSleuth signatures, Unreal member offsets, EngineTick targets, or
Palworld-specific hook definitions required changes.

Launcher configuration

Scoped deployments can require the expected entrypoint type with:

UE4SS_SELINUX_PREFLIGHT=strict
UE4SS_EXPECTED_SELINUX_TYPE=palworld_ue4ss_exec_t

The launcher exits before installing runtime hooks when strict validation
fails. This replaces a delayed executable-memory fault with an immediate,
actionable diagnostic.

Downloads

• RE-UE4SS-Linux-0.1.1-x86_64.tar.gz
• RE-UE4SS-Linux-0.1.1-x86_64-debug.tar.gz
• RELEASE-MANIFEST.txt
• Accompanying SHA-256 files

The runtime archive contains the loader, process-scoped launcher, settings,
bundled mod files, installation documentation, provenance metadata, and
internal checksums.

Compatibility scope

This prerelease does not claim compatibility with every Unreal Engine game,
engine version, Linux distribution, or third-party UE4SS mod.

Compatibility applies only to combinations explicitly recorded in the Linux
compatibility matrix. Stop the host process to unload UE4SS; do not use
dlclose.

RE-UE4SS Linux v0.1.0

RE-UE4SS Linux v0.1.0

This is the first native Linux downstream prerelease of RE-UE4SS.

Validated target

• Palworld Dedicated Server 1.0.1.100619
• Steam build ID 24181105
• Unreal Engine 5.1.1
• Native x86-64 Linux server
• Fedora Linux 43 validation host
• glibc-based headless runtime
• PalServer SHA-256 788649fa1592160faa7bcf07ccd16d474ebeaae954717bc32284b5a43028d8e7
• PalServer ELF build ID 7f7e167407984ec3
• Final acceptance matrix: 36 fresh-process cycles
  (1 smoke, 5 core-only, 20 Lua-only, 5 native-only,
  and 5 Lua-plus-native)
• Runtime acceptance source: the commit referenced by the
  linux-v0.1.0 tag and recorded in RELEASE-MANIFEST.txt
• Runtime-accepted packaged loader identity: recorded in
  RELEASE-MANIFEST.txt and the package's BUILD-METADATA.txt

The release source commit is the commit referenced by the linux-v0.1.0 tag
and recorded inside the package's BUILD-METADATA.txt.

Highlights

• Native x86-64 ELF libUE4SS.so
• Process-scoped LD_PRELOAD launcher
• Lua mod discovery and execution
• Native Linux C++ .so mod loading
• UObject, UClass, UWorld, FName, FString, and FText access
• Reflected property reads and controlled writes
• Reflected UFunction invocation and parameter handling
• Native and Lua hook callbacks
• Repeated fresh-process startup and graceful shutdown
• Scoped SELinux operation without enabling global execheap
• Reproducible runtime and separate debug-symbol archives
• Bundled optional mods disabled by default

Downloads

• RE-UE4SS-Linux-0.1.0-x86_64.tar.gz
• RE-UE4SS-Linux-0.1.0-x86_64-debug.tar.gz
• RELEASE-MANIFEST.txt, containing archive SHA-256 values and build identity

The runtime archive contains the loader, launcher, settings, bundled mod files,
installation documentation, provenance metadata, and internal checksums.

Compatibility scope

This prerelease does not claim compatibility with every Unreal Engine game,
engine version, Linux distribution, or existing third-party UE4SS mod.

Compatibility applies only to combinations explicitly recorded in the Linux
compatibility matrix. Existing third-party Linux mod compatibility remains
under evaluation.

Do not unload UE4SS using dlclose. Stop the host process to unload the loader.

Native Linux prerelease limitations

• The per-mod Lua asynchronous worker is disabled on native Linux to avoid an intermittent shutdown-time std::system_error/SIGABRT. Standard Lua mod loading and tested Unreal hooks remain operational. Lua features that require the asynchronous worker may be unavailable.
• One non-reproduced shutdown-time SIGSEGV occurred during extended diagnostic testing. Twenty subsequent cycles with core capture enabled completed cleanly. This is recorded as a rare shutdown observation and is not considered a blocker for the v0.1.0 prerelease.
• Marker-free raw LD_PRELOAD and explicit dlopen auto-start are fail-closed by default. Set UE4SS_ALLOW_LEGACY_START=1 only for deliberate legacy compatibility; the supported path is run_ue4ss.sh.