fix(shader): avoid unsafe Windows cache directory traversal

core/libs/prx/libSceAgcDriver/CMakeLists.txt

@@ -2060,6 +2060,24 @@ if(BUILD_TESTING)
         set_tests_properties(agc_driver_partially_resident_pending_stores PROPERTIES ENVIRONMENT_MODIFICATION "PATH=path_list_prepend:$<TARGET_FILE_DIR:libc>")
     endif()
     add_test(NAME agc_shader_disk_cache_large_file COMMAND agc_shader_disk_cache_tests --large-file)
+    if(Python3_Interpreter_FOUND)
+        set(housekeepingModes plain)
+        if(WIN32)
+            list(APPEND housekeepingModes extended extended-long device)
+        else()
+            list(APPEND housekeepingModes plain-long)
+        endif()
+        foreach(housekeepingMode IN LISTS housekeepingModes)
+            set(housekeepingTest agc_shader_cache_housekeeping_${housekeepingMode})
+            add_test(NAME ${housekeepingTest} COMMAND ${Python3_EXECUTABLE}
+                ${CMAKE_CURRENT_SOURCE_DIR}/tests/test_shader_cache_housekeeping.py
+                $<TARGET_FILE:agc_shader_disk_cache_tests> ${housekeepingMode})
+            set_tests_properties(${housekeepingTest} PROPERTIES TIMEOUT 20)
+            if(WIN32)
+                set_tests_properties(${housekeepingTest} PROPERTIES ENVIRONMENT_MODIFICATION "PATH=path_list_prepend:$<TARGET_FILE_DIR:libc>")
+            endif()
+        endforeach()
+    endif()
     set_tests_properties(agc_shader_disk_cache_large_file PROPERTIES SKIP_RETURN_CODE 77 RUN_SERIAL TRUE WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}" TIMEOUT 240)
     if(WIN32)
         set_tests_properties(agc_shader_disk_cache_large_file PROPERTIES ENVIRONMENT_MODIFICATION "PATH=path_list_prepend:$<TARGET_FILE_DIR:libc>")

core/libs/prx/libSceAgcDriver/tests/ShaderDiskCache.cpp

@@ -2259,6 +2259,14 @@ void verifyDefaultDirectory(const char* self) {
 
 int main(int argc, char** argv) {
     try {
+        if (argc == 2 && std::string_view(argv[1]) == "--housekeeping-safety") {
+            const auto directory = ShaderDiskCache::EntryDirectory();
+            require(!directory.empty(), "the housekeeping fixture cache is disabled");
+            ShaderDiskCache::Shutdown();
+            require(ShaderDiskCache::Writers() == 0, "the housekeeping writer did not stop");
+            std::cout << "housekeeping version " << directory.filename().string() << '\n';
+            return 0;
+        }
         if (argc == 2 && std::string_view(argv[1]) == "--resource-plan-codec") {
             verifyResultRoundTrip();
             verifyEntryRoundTrip();

core/libs/prx/libSceAgcDriver/tests/test_shader_cache_housekeeping.py

@@ -0,0 +1,100 @@
+import os
+import re
+import shutil
+import subprocess
+import sys
+import tempfile
+import time
+from pathlib import Path
+
+
+def native(path):
+    return Path('\\\\?\\' + str(path)) if os.name == 'nt' else path
+
+
+def snapshot(directory):
+    return {str(path.relative_to(directory)): None if path.is_dir() else path.read_bytes()
+            for path in directory.rglob('*')}
+
+
+def main():
+    executable = str(Path(sys.argv[1]).resolve())
+    mode = sys.argv[2]
+    assert mode in ('plain', 'plain-long', 'extended', 'extended-long', 'device')
+    assert os.name == 'nt' or mode in ('plain', 'plain-long')
+    sandbox = Path(tempfile.mkdtemp(prefix='aps5-housekeeping-')).resolve()
+    temporary = Path(tempfile.gettempdir()).resolve()
+    try:
+        outside = sandbox / 'outside'
+        outside.mkdir()
+        environment = dict(os.environ, ANYPS5_NO_SHADER_CACHE='0',
+                           ANYPS5_SHADER_CACHE_DIR=str(sandbox / 'bootstrap'))
+
+        def run():
+            return subprocess.run([executable, '--housekeeping-safety'], cwd=outside,
+                                  env=environment, stdout=subprocess.PIPE,
+                                  stderr=subprocess.STDOUT, text=True, errors='replace', timeout=5)
+
+        bootstrap = run()
+        assert bootstrap.returncode == 0, bootstrap.stdout
+        match = re.search(r'housekeeping version ([0-9a-f]{16})', bootstrap.stdout)
+        assert match, bootstrap.stdout
+        version = match.group(1)
+        siblings = [digit + version[1:] for digit in '0123' if digit != version[0]]
+        root = sandbox / 'cache-\u00e4\u6f22'
+        if mode.endswith('long'):
+            while len(str(root)) < 230:
+                root /= 'd' * 40
+            root /= 'd' * max(1, 269 - len(str(root)))
+            assert len(str(root)) >= 270
+        root = native(root)
+        current = root / version
+        current.mkdir(parents=True)
+        old = time.time() - 30 * 24 * 3600
+        for parent in (root, outside):
+            for index, name in enumerate(siblings):
+                folder = parent / name
+                folder.mkdir()
+                (folder / 'sentinel').write_bytes(b'preserve outside the cache root')
+                if index != 1:
+                    (folder / 'last-used').write_bytes(b'')
+                    os.utime(folder / 'last-used', (old if index == 0 else time.time(),) * 2)
+                os.utime(folder, (old, old))
+        (outside / 'outside.tmp.1').write_bytes(b'not a cache temporary')
+        os.utime(outside / 'outside.tmp.1', (old, old))
+        for name in ('shader.bin', 'old.tmp.1', 'fresh.tmp.1', 'last-used'):
+            (current / name).write_bytes(b'cached bytes')
+        for name in ('shader.bin', 'old.tmp.1', 'last-used'):
+            os.utime(current / name, (old, old))
+        before = snapshot(outside)
+        if mode.startswith('extended'):
+            environment['ANYPS5_SHADER_CACHE_DIR'] = str(root)
+        elif mode == 'device':
+            environment['ANYPS5_SHADER_CACHE_DIR'] = '\\\\.\\' + str(root)[4:]
+        else:
+            environment['ANYPS5_SHADER_CACHE_DIR'] = str(root)[4:] if os.name == 'nt' else str(root)
+        started = time.time()
+        try:
+            result = run()
+        except subprocess.TimeoutExpired as error:
+            assert snapshot(outside) == before, 'housekeeping changed files outside its root'
+            raise AssertionError('housekeeping did not return within five seconds; child terminated') from error
+        assert snapshot(outside) == before, 'housekeeping changed files outside its root'
+        assert result.returncode == 0, result.stdout
+        assert 'housekeeping version ' + version in result.stdout, result.stdout
+        assert (current / 'last-used').stat().st_mtime >= started - 2, 'active cache stamp was not refreshed'
+        skipped = mode.startswith('extended') or mode == 'device'
+        for name in siblings[:2]:
+            assert (root / name).exists() == skipped, 'unexpected stale cache directory eviction'
+        assert (root / siblings[2] / 'sentinel').read_bytes() == b'preserve outside the cache root'
+        assert (current / 'old.tmp.1').exists() == skipped, 'unexpected old temporary removal'
+        assert (current / 'fresh.tmp.1').read_bytes() == b'cached bytes'
+        assert (current / 'shader.bin').read_bytes() == b'cached bytes'
+        print(mode + ': returned, active stamp refreshed, outside tree intact, eviction policy verified')
+    finally:
+        assert sandbox.parent == temporary and sandbox.name.startswith('aps5-housekeeping-')
+        shutil.rmtree(native(sandbox))
+
+
+if __name__ == '__main__':
+    main()

core/shader/recompiler/ShaderDiskCache.cpp

@@ -1615,6 +1615,11 @@ class DiskStore {
         const auto stamp = directory / "last-used";
         std::ofstream(stamp, std::ios::binary | std::ios::trunc).close();
         std::filesystem::last_write_time(stamp, std::filesystem::file_time_type::clock::now(), error);
+#ifdef _WIN32
+        auto nativeRoot = root;
+        nativeRoot.make_preferred();
+        if (nativeRoot.native().starts_with(L"\\\\?\\") || nativeRoot.native().starts_with(L"\\\\.\\")) return;
+#endif
         const auto now = std::filesystem::file_time_type::clock::now();
         for (std::filesystem::directory_iterator it(root, error), end; !error && it != end; it.increment(error)) {
             const auto name = it->path().filename().string();

docs/dev/debt/shader.md

@@ -23,6 +23,8 @@
 
 ### Functional
 
+- [Windows cache housekeeping](../../../core/shader/recompiler/ShaderDiskCache.cpp): eviction of old versions and temporary files is skipped for `\\?\` and `\\.\` cache roots because the supported WinLibs directory iterator can enumerate the process working directory for long prefixed paths. The active version's `last-used` stamp update still runs; it fails for long `\\.\` aliases with the supported toolchain. Ordinary Windows directory enumeration remains subject to MAX_PATH. Prebuilt directory discovery is not guarded for prefixed roots.
+
 - [f64 compares](../../../core/shader/recompiler/Translation/src/CompareInstructions.cpp) flush denormal inputs to signed zero when bit 0 of the `FLOAT_MODE` f16/f64 denormal field is clear (modes 0 and 2); modes 1 and 3 and an unknown mode keep them. This follows the RDNA2 ISA section 6.4 and LLVM's sign-preserving AMDGPU denormal modes. The gfx1036 audit in [#981](https://github.com/boykopovar/AnyPS5/issues/981#issuecomment-6070046381) reports mode-sensitive `VopcCompareF64` results. Class compares still inspect the original bits. The full four-mode matrix has not been newly measured on AMD hardware or the PS5's gfx1013.
 
 - [Unlinked calls](../../../core/shader/recompiler/ControlFlow/src/GraphBuilder.cpp) - the `s_swappc_b64` a table call's compare chain falls back to, when its target matches no linked copy, records the `UnlinkedCall` fault with the target and the program counter and stops the invocation, or continues after the call in programs whose faults do not stop invocations (see `bdaStopsInvocations`). The driver lists those calls in the request (`linkedCallFallbacks`), and it reports the fault like a BDA fault, naming the target: a dispatch that checks its faults when it completes throws, one whose check runs in a deferred write-back logs it and continues. The hardware would jump to the target, which is not modelled. Any other `s_swappc_b64` whose target is not resolved still throws when the shader is compiled.