fix(python): validate shared pyc header facts

bridge/pwntools/layout_impl.py

@@ -135,25 +135,13 @@ def inspect_elf(path, cache):
     from pwnlib.context import context
     with context.local(cache_dir=str(cache), log_level="warning"):
         from elftools.common.exceptions import ELFError
-        from elftools.common.utils import struct_parse
         from elftools.elf.elffile import ELFFile
         from pwnlib.elf import ELF
         try:
             headers = ELFFile(io.BytesIO(content))
             section_count = headers.num_sections()
             if section_count:
-                if headers.header.e_shentsize < headers.structs.Elf_Shdr.sizeof():
-                    raise LayoutFailure("format", "ELF section-header entry is shorter than the required structure.")
                 location(headers.header.e_shoff, section_count * headers.header.e_shentsize, len(content))
-            # Upstream string/symbol/relocation access reads stored stream bytes,
-            # while this profile reports logical names and file coordinates.
-            # Admit those encodings before LayoutELF populates convenience maps.
-            for index in range(section_count):
-                raw_header = struct_parse(headers.structs.Elf_Shdr, headers.stream,
-                                          stream_pos=headers.header.e_shoff + index * headers.header.e_shentsize)
-                if raw_header.sh_flags & 0x800 and raw_header.sh_type in (
-                        "SHT_STRTAB", "SHT_SYMTAB", "SHT_DYNSYM", "SHT_REL", "SHT_RELA", "SHT_RELR", "SHT_DYNAMIC"):
-                    raise LayoutFailure("unsupported-target", f"ELF section {index} ({raw_header.sh_type}) is SHF_COMPRESSED; logical metadata and its source coordinates are not decoded by this profile.")
             segment_count = headers.num_segments()
             if segment_count:
                 location(headers.header.e_phoff, segment_count * headers.header.e_phentsize, len(content))

bridge/pwntools/test_layout.py

@@ -1,87 +0,0 @@
-"""Producer admission regressions; no pwntools imports or target execution."""
-from contextlib import nullcontext
-import importlib.metadata
-from pathlib import Path
-import runpy
-import sys
-import tempfile
-import types
-import unittest
-from unittest.mock import patch
-
-
-layout = runpy.run_path(str(Path(__file__).with_name("layout_impl.py")))
-
-
-class UpstreamReached(RuntimeError):
-    pass
-
-
-class LayoutStorageTests(unittest.TestCase):
-    def inspect(self, section_type, flags, section_stride=64):
-        class Headers:
-            header = types.SimpleNamespace(e_shoff=64, e_shentsize=section_stride, e_shstrndx=0)
-            structs = types.SimpleNamespace(Elf_Shdr=types.SimpleNamespace(sizeof=lambda: 64))
-            stream = object()
-
-            def num_sections(self): return 2
-            def num_segments(self): return 0
-            def get_shstrndx(self): return 0
-            def _get_section_header(self, index):
-                return types.SimpleNamespace(sh_type="SHT_NULL" if index == 0 else section_type,
-                                             sh_flags=0 if index == 0 else flags)
-
-        class Elf:
-            def __init__(self, *_args, **_kwargs):
-                raise UpstreamReached("No artifact decoding or emulation is allowed in this test")
-
-        modules = {name: types.ModuleType(name) for name in (
-            "pwnlib", "pwnlib.context", "pwnlib.elf", "elftools", "elftools.common",
-            "elftools.common.exceptions", "elftools.common.utils", "elftools.elf", "elftools.elf.elffile")}
-        modules["pwnlib.context"].context = types.SimpleNamespace(local=lambda **_kwargs: nullcontext())
-        modules["pwnlib.elf"].ELF = Elf
-        modules["elftools.common.exceptions"].ELFError = type("ELFError", (Exception,), {})
-        modules["elftools.elf.elffile"].ELFFile = lambda _stream: Headers()
-        modules["elftools.common.utils"].struct_parse = lambda _struct, _stream, stream_pos: Headers()._get_section_header((stream_pos - 64) // max(section_stride, 1))
-        content = bytearray(64 + 2 * max(section_stride, 64))
-        content[:7] = b"\x7fELF\x02\x01\x01"
-        content[16:18] = (1).to_bytes(2, "little")  # ET_REL
-        content[18:20] = (62).to_bytes(2, "little")
-        content[40:48] = (64).to_bytes(8, "little")
-        content[58:60] = section_stride.to_bytes(2, "little")
-        content[60:62] = (2).to_bytes(2, "little")
-        with tempfile.TemporaryDirectory() as directory:
-            snapshot = Path(directory) / "object.snapshot"
-            snapshot.write_bytes(content)
-            with patch.dict(sys.modules, modules), patch.object(importlib.metadata, "version", side_effect=layout["PACKAGES"].__getitem__):
-                return layout["inspect_elf"](snapshot, Path(directory) / "cache")
-
-    def test_compressed_interpreted_storage_refuses_before_upstream_decoding(self):
-        for section_type in ("SHT_STRTAB", "SHT_SYMTAB", "SHT_DYNSYM", "SHT_REL", "SHT_RELA", "SHT_RELR", "SHT_DYNAMIC"):
-            with self.subTest(section_type=section_type):
-                with self.assertRaises(layout["LayoutFailure"]) as raised:
-                    self.inspect(section_type, 0x800)
-                self.assertEqual(raised.exception.reason, "unsupported-target")
-                self.assertIn("SHF_COMPRESSED", str(raised.exception))
-                with self.assertRaises(UpstreamReached):
-                    self.inspect(section_type, 0)
-
-    def test_uninterpreted_compressed_payload_does_not_change_admission(self):
-        with self.assertRaises(UpstreamReached):
-            self.inspect("SHT_PROGBITS", 0x800)
-
-    def test_short_section_header_stride_refuses_before_raw_header_scan(self):
-        for stride in (0, 1, 63):
-            with self.subTest(stride=stride):
-                with self.assertRaises(layout["LayoutFailure"]) as raised:
-                    self.inspect("SHT_PROGBITS", 0, stride)
-                self.assertEqual(raised.exception.reason, "format")
-                self.assertIn("section-header entry", str(raised.exception))
-        for stride in (64, 96):
-            with self.subTest(stride=stride):
-                with self.assertRaises(UpstreamReached):
-                    self.inspect("SHT_PROGBITS", 0, stride)
-
-
-if __name__ == "__main__":
-    unittest.main()

docs/guides/native/binary-diagnostics.md

@@ -44,11 +44,6 @@ before dependency seeks. Structural inventory and the convenience-map engine
 still parse the snapshot separately; eliminating that remaining duplication
 requires preserving the upstream GOT/PLT and mitigation facts.
 
-The layout profile returns `unsupported_target` for `SHF_COMPRESSED` string,
-symbol, relocation or dynamic metadata sections before upstream convenience-map
-decoding. Their logical names and entry coordinates cannot be read from the
-compressed file bytes. Other compressed payload sections remain opaque.
-
 ## Interpreting results
 
 - Artifact path, SHA-256 and size identify original selected bytes. All parsing
@@ -483,13 +478,6 @@ section directory with neither a dynamic symbol table nor a dynamic segment
 reports a complete empty inventory. Mach-O exports are reported by
 `inspect_macho`.
 
-ELF export tables marked `SHF_COMPRESSED` are not decompressed. A compressed
-dynamic symbol table or its string table reports `unsupported` coverage rather
-than treating stored bytes as symbols or names. Compressed version tables or
-their string tables keep readable export rows with `partial` coverage and
-unresolved versions. When version definition storage is compressed, requirement
-names also remain unknown because unseen definitions may override them.
-
 `max_file_bytes` defaults to 256 MiB (maximum 512 MiB; CLI `--max-file-bytes`).
 Export directories in PE headers are read like those in sections. An export or
 dynamic symbol table above 262144 entries, more than 262144 rows, or more than

docs/guides/native/elf-unwind-ranges.md

@@ -173,12 +173,5 @@ on one page share a fixed 16 MiB text allowance; a page that exceeds it fails
 with a resource error whose recovery is a smaller `limit`, because
 `max_ranges` and `max_file_bytes` do not raise it.
 
-Compressed symbol or name tables and symbol-table links that do not name a
-file-backed `SHT_STRTAB` section leave symbol names unknown and coverage
-incomplete; decoded FDE ranges remain available.
-
-A compressed dynamic section cannot supply `DT_PLTGOT`. Without another
-observed GOT base, affected data-relative unwind pointers remain unresolved.
-
 Malformed ELF headers fail without partial success. This workflow does not
 execute the image, evaluate CFA programs, or follow indirect pointers.

docs/guides/native/native-initializers.md

@@ -150,11 +150,6 @@ A symbol name that cannot be read, because its string table is missing or its
 offset lies outside the table, is reported as no name and makes the report
 `incomplete` with a counted limitation. Name offset 0 is the empty name.
 
-ELF sections marked `SHF_COMPRESSED` are not decoded as initializer slots,
-symbols, names or relocation records. Affected facts remain unresolved and
-coverage is incomplete; other readable tables remain available. An explicit
-`DT_SYMTAB` must identify the decoded symbol table used for dynamic relocations.
-
 The dynamic relocation tables are read in steps that yield to other work and
 observe cancellation, so a large `DT_RELR` table does not block the server.
 

src/application/python/PythonPycService.test.ts

@@ -66,6 +66,28 @@ const report: PythonPyc = {
   ],
 };
 
+it.each([
+  {
+    flags: 1,
+    hash_based: true,
+    source_hash_hex: "",
+    source_mtime: null,
+    source_size: null,
+  },
+  { flags: 1 },
+])("refuses inconsistent provider header facts %j", async (header) => {
+  const result = await new PythonPycService({
+    close: async () => {},
+    identity,
+    inspect: async () =>
+      ok({ ...report, header: { ...report.header, ...header } }),
+  }).inspect({ path: report.artifact.path });
+  expect(result).toMatchObject({
+    ok: false,
+    error: { _tag: "AnalysisOutputError" },
+  });
+});
+
 it("rejects a relative path and extra arguments before reading", async () => {
   let calls = 0;
   const service = new PythonPycService({

src/domain/python/pythonPyc.test.ts

@@ -3,9 +3,49 @@ import {
   inspectPythonPycInputSchema,
   pythonPycMarshalProfile,
   PYTHON_PYC_MARSHAL_PROFILES,
+  pythonPycHeaderSchema,
 } from "./pythonPyc.js";
 import { pythonBytecodeIdentity } from "./pythonBytecodeIdentity.js";
 
+const hashHeader = {
+  magic: 3531,
+  python_version: "3.12",
+  code_layout: "py311",
+  flags: 3,
+  hash_based: true,
+  check_source: true,
+  source_hash_hex: "0123456789abcdef",
+  source_mtime: null,
+  source_size: null,
+};
+
+it.each(["", "ab", "g".repeat(16)])(
+  "rejects an invalid source hash %j",
+  (source_hash_hex) => {
+    expect(
+      pythonPycHeaderSchema.safeParse({ ...hashHeader, source_hash_hex })
+        .success,
+    ).toBe(false);
+  },
+);
+
+it.each([
+  { hash_based: false },
+  { check_source: false },
+  { source_hash_hex: null },
+  { source_mtime: 0 },
+  { source_size: 0 },
+])("keeps header facts consistent with the recorded flags: %j", (changed) => {
+  expect(
+    pythonPycHeaderSchema.safeParse({ ...hashHeader, ...changed }).success,
+  ).toBe(false);
+});
+
+it("preserves unknown raw header flags and valid hash bytes", () => {
+  const header = { ...hashHeader, flags: 0x80000003 };
+  expect(pythonPycHeaderSchema.parse(header)).toEqual(header);
+});
+
 it("keeps pinned CPython identity separate from standalone marshal coverage", () => {
   expect(pythonPycMarshalProfile(3394)).toEqual({
     code_layout: "py37",

src/domain/python/pythonPyc.ts

@@ -205,17 +205,53 @@ const pythonCodeObjectSchema = z.strictObject({
 });
 export type PythonPycCodeObject = z.infer<typeof pythonCodeObjectSchema>;
 
-export const pythonPycHeaderSchema = z.strictObject({
-  magic: z.number().int().min(0).max(0xffff),
-  python_version: z.string().min(1),
-  code_layout: z.enum(PYTHON_PYC_CODE_LAYOUTS),
-  flags: uint,
-  hash_based: z.boolean(),
-  check_source: z.boolean(),
-  source_hash_hex: z.string().nullable(),
-  source_mtime: uint.nullable(),
-  source_size: uint.nullable(),
-});
+export const pythonPycHeaderSchema = z
+  .strictObject({
+    magic: z.number().int().min(0).max(0xffff),
+    python_version: z.string().min(1),
+    code_layout: z.enum(PYTHON_PYC_CODE_LAYOUTS),
+    flags: uint,
+    hash_based: z.boolean(),
+    check_source: z.boolean(),
+    source_hash_hex: z
+      .string()
+      .regex(/^[0-9a-f]{16}$/u)
+      .nullable(),
+    source_mtime: uint.nullable(),
+    source_size: uint.nullable(),
+  })
+  .superRefine((header, context) => {
+    for (const [field, flag] of [
+      ["hash_based", PYTHON_PYC_HASH_BASED],
+      ["check_source", PYTHON_PYC_CHECK_SOURCE],
+    ] as const)
+      if (header[field] !== ((header.flags & flag) !== 0))
+        context.addIssue({
+          code: "custom",
+          path: [field],
+          message: `${field} disagrees with its recorded header flag.`,
+        });
+    if (header.hash_based === (header.source_hash_hex === null))
+      context.addIssue({
+        code: "custom",
+        path: ["source_hash_hex"],
+        message:
+          "Hash-based pycs require an 8-byte source hash; others must omit it.",
+      });
+    if (header.hash_based === (header.source_mtime !== null))
+      context.addIssue({
+        code: "custom",
+        path: ["source_mtime"],
+        message: "Timestamp pycs require mtime; hash-based pycs must omit it.",
+      });
+    if (header.hash_based === (header.source_size !== null))
+      context.addIssue({
+        code: "custom",
+        path: ["source_size"],
+        message:
+          "Timestamp pycs require source_size; hash-based pycs must omit it.",
+      });
+  });
 
 /** Bounded CPython 3.7–3.13 pyc observation; marshal is walked, bytecode is not decompiled. */
 export const pythonPycSchema = z
@@ -253,29 +289,6 @@ export const pythonPycSchema = z
         message: "Marshal byte count disagrees with the header-stripped file.",
       });
     }
-    if (report.header.hash_based === (report.header.source_hash_hex === null)) {
-      context.addIssue({
-        code: "custom",
-        path: ["header", "source_hash_hex"],
-        message:
-          "Hash-based pycs require an 8-byte source hash; others must omit it.",
-      });
-    }
-    if (report.header.hash_based === (report.header.source_mtime !== null)) {
-      context.addIssue({
-        code: "custom",
-        path: ["header", "source_mtime"],
-        message: "Timestamp pycs require mtime; hash-based pycs must omit it.",
-      });
-    }
-    if (report.header.hash_based === (report.header.source_size !== null)) {
-      context.addIssue({
-        code: "custom",
-        path: ["header", "source_size"],
-        message:
-          "Timestamp pycs require source_size; hash-based pycs must omit it.",
-      });
-    }
     if (report.coverage.code_objects !== report.code_objects.length) {
       context.addIssue({
         code: "custom",

src/gpu/GpuElfKernels.ts

@@ -43,7 +43,7 @@ const sectionBytes = (
   section: NativeSection,
   budget?: CudaMetadataBudget,
 ): Promise<Buffer> => {
-  if (!section.file_backed || section.compressed)
+  if (!section.file_backed || (section.flags & 0x800n) !== 0n)
     rejectGpu("GPU metadata section has no supported uncompressed file range");
   budget?.read(gpuCount(section.size));
   return source.read(gpuCount(section.offset), gpuCount(section.size));

src/gpu/GpuInventory.ts

@@ -194,7 +194,10 @@ export class GpuInventory {
             continue;
           }
           if (!isGpuSection(section.name)) continue;
-          if (!section.file_backed || section.compressed) {
+          if (
+            !section.file_backed ||
+            (directory.format === "elf" && (section.flags & 0x800n) !== 0n)
+          ) {
             this.discovery = "partial";
             const message = `GPU section ${section.index} has no supported uncompressed file range`;
             this.#retain(message);

src/native/android/AndroidJniLibrary.ts

@@ -340,7 +340,11 @@ export const inspectAndroidJniLibrary = async (
       for (const section of directory.sections) {
         if ((section.flags & 3n) !== 3n || section.size === 0n) continue;
         active();
-        if (section.compressed || !section.file_backed || section.type === 8) {
+        if (
+          (section.flags & 0x800n) !== 0n ||
+          !section.file_backed ||
+          section.type === 8
+        ) {
           tablesStatus = "partial";
           unknowns.add(
             "Allocated writable sections without ordinary file bytes were not scanned; runtime-built tables remain unknown",

src/native/elf/ElfUnwindTables.test.ts

@@ -462,33 +462,6 @@ const findSection = (bytes: Buffer, name: string) => {
   throw new Error(`fixture has no ${name}`);
 };
 
-it.each(["compressed-symbols", "compressed-names", "non-string-names"])(
-  "retains unwind ranges without interpreting %s as ordinary symbol storage",
-  (storage) => {
-    const bytes = elfUnwindFixture({ header: "match" });
-    expect(parse(bytes).ranges[0]?.symbol?.text).toBe("alpha");
-    const section = findSection(
-      bytes,
-      storage === "compressed-symbols" ? ".symtab" : ".strtab",
-    );
-    if (storage === "non-string-names")
-      bytes.writeUInt32LE(1, section.headerOffset + 4);
-    else bytes.writeBigUInt64LE(0x800n, section.headerOffset + 8);
-
-    const report = parse(bytes);
-    expect(report.ranges.map(({ start }) => start)).toEqual([
-      address(UNWIND_FN_A),
-      address(UNWIND_FN_B),
-    ]);
-    expect(report.ranges.map(({ symbol }) => symbol)).toEqual([null, null]);
-    expect(report.coverage).toMatchObject({
-      status: "incomplete",
-      ranges_with_symbols: 0,
-      eh_frame_hdr_agreement: "agree",
-    });
-  },
-);
-
 it("keeps .eh_frame ranges when .debug_frame is SHT_NOBITS", () => {
   const report = parse(
     elfUnwindFixture({
@@ -618,18 +591,6 @@ it("caps symbol lookup across .symtab and .dynsym together", () => {
   );
 });
 
-it("keeps the symbol scan allowance for later tables when an earlier table has no string table", () => {
-  const bytes = elfUnwindFixture({ header: "match", symbolCap: true });
-  const section = findSection(bytes, ".symtab");
-  bytes.writeUInt32LE(0, section.headerOffset + 40);
-  const report = parse(bytes);
-  expect(report.ranges[0]?.symbol?.text).toBe("alpha");
-  expect(report.coverage.status).toBe("incomplete");
-  expect(report.limitations).not.toContain(
-    "Symbol tables were capped at 65536 combined entries.",
-  );
-});
-
 it.each([".eh_frame", ".eh_frame_hdr"] as const)(
   "reports coverage incomplete when a duplicate %s is ignored",
   (duplicate) => {
@@ -704,22 +665,6 @@ it.each([
   },
 );
 
-it("keeps the GOT unknown when compressed dynamic storage resembles decoded entries", () => {
-  const bytes = elfUnwindFixture({ header: "match", datarel: "dynamic" });
-  const section = findSection(bytes, ".dynamic");
-  // The payload still resembles ordinary DT_PLTGOT/DT_NULL entries, but the
-  // declaration makes it opaque compressed storage, not a decoded table.
-  bytes.writeBigUInt64LE(0x800n, section.headerOffset + 8);
-  const report = parse(bytes);
-  expect(report.ranges.map((range) => range.start)).not.toContain(
-    address(UNWIND_FN_A),
-  );
-  expect(report.coverage.status).toBe("incomplete");
-  expect(report.limitations).toContain(
-    "A DW_EH_PE_datarel .eh_frame value needs a GOT base that could not be determined; that value is unresolved.",
-  );
-});
-
 it("caps .eh_frame_hdr rows at the max_ranges budget and marks the comparison incomplete", () => {
   const report = parse(elfUnwindFixture({ header: "duplicate-row" }), {
     max_ranges: 2,

src/native/elf/ElfUnwindTables.ts

@@ -34,7 +34,6 @@ const AUG_R = 0x52;
 const AUG_S = 0x53;
 const AUG_B = 0x42;
 const SHT_SYMTAB = 2;
-const SHT_STRTAB = 3;
 const SHT_DYNAMIC = 6;
 const SHT_NOBITS = 8;
 const SHT_DYNSYM = 11;
@@ -50,6 +49,7 @@ const SHN_ABS = 0xfff1;
 const SHN_LORESERVE = 0xff00;
 const SHF_ALLOC = 2n;
 const SHF_EXECINSTR = 4n;
+const SHF_COMPRESSED = 0x800n;
 
 const {
   cfa: CFA_LIMITATION,
@@ -639,7 +639,7 @@ export const parseElfUnwindRanges = (
           ? ".eh_frame_hdr is declared but not file-backed."
           : ".eh_frame_hdr extends past the end of the file and was not decoded.",
       );
-    } else if (hdrSection.compressed) {
+    } else if ((hdrSection.flags & SHF_COMPRESSED) !== 0n) {
       headerLocation = placement.location;
       headerStatus = "incomplete";
       fail(".eh_frame_hdr is SHF_COMPRESSED and was not decompressed.");
@@ -705,7 +705,7 @@ export const parseElfUnwindRanges = (
     } else if (frameLocation === null) {
       frameStatus = "incomplete";
       fail(".eh_frame lies outside the file.");
-    } else if (ehSection.compressed) {
+    } else if ((ehSection.flags & SHF_COMPRESSED) !== 0n) {
       frameStatus = "incomplete";
       fail(".eh_frame is SHF_COMPRESSED and was not decompressed.");
     } else {
@@ -1135,12 +1135,7 @@ const resolveGotBase = (
       ? undefined
       : { offset: dynamicProgram.offset, fileSize: dynamicProgram.size }) ??
     directory.sections
-      .filter(
-        (section) =>
-          section.type === SHT_DYNAMIC &&
-          section.file_backed &&
-          !section.compressed,
-      )
+      .filter((section) => section.type === SHT_DYNAMIC && section.file_backed)
       .map((section) => ({
         offset: section.offset,
         fileSize: section.size,
@@ -1819,10 +1814,6 @@ const scanSymbols = (
   let remaining = MAX_ELF_UNWIND_SYMBOLS;
   for (const table of tables) {
     assertArtifactReadActive(signal);
-    if (table.compressed) {
-      fail("A symbol table is SHF_COMPRESSED and was not decompressed.");
-      continue;
-    }
     const width = table.entry_size === 0n ? standard : Number(table.entry_size);
     if (width !== standard) {
       fail(
@@ -1838,15 +1829,6 @@ const scanSymbols = (
     const size = Number(table.size);
     if (size % width !== 0)
       fail("A symbol table size is not a multiple of its entry width.");
-    const strings = byIndex.get(table.link);
-    if (strings?.type !== SHT_STRTAB || !strings.file_backed) {
-      fail("A symbol table does not link to a file-backed SHT_STRTAB section.");
-      continue;
-    }
-    if (strings.compressed) {
-      fail("A symbol string table is SHF_COMPRESSED and was not decompressed.");
-      continue;
-    }
     let count = Math.floor(size / width);
     if (count > remaining) {
       fail(
@@ -1855,10 +1837,15 @@ const scanSymbols = (
       count = remaining;
     }
     remaining -= count;
-    const stringBytes = bytes.subarray(
-      Number(strings.offset),
-      Number(strings.offset + strings.size),
-    );
+    const strings = byIndex.get(table.link);
+    const stringBytes =
+      strings !== undefined && strings.file_backed
+        ? bytes.subarray(
+            Number(strings.offset),
+            Number(strings.offset + strings.size),
+          )
+        : null;
+    if (stringBytes === null) fail("A symbol string table could not be read.");
     // Observation per string-table offset; null when the name is unreadable.
     const names = new Map<number, SymbolName | null>();
     for (let index = 0; index < count; index += 1) {
@@ -1891,7 +1878,7 @@ const scanSymbols = (
         if (owner !== undefined) address += owner.address;
       }
       // Only a symbol at a decoded FDE start can name a range.
-      if (!wanted.has(address)) continue;
+      if (stringBytes === null || !wanted.has(address)) continue;
       let name = names.get(symbol.name_offset);
       if (name === undefined) {
         const observed = observeElfStringTableEntry(

src/native/exports/NativeExportParser.test.ts

@@ -1,5 +1,4 @@
 import { describe, expect, it, vi } from "vitest";
-import { deflateSync } from "node:zlib";
 
 import {
   elfExportImage,
@@ -23,172 +22,6 @@ const parse = (bytes: Buffer) =>
     parseNativeExports(bytes, artifact),
   );
 
-/** Encode real gABI compressed storage, retaining logical section links. */
-const compressExportSection = (
-  bytes: Buffer,
-  sectionIndex: number,
-  versionStrings = false,
-): Buffer => {
-  const wide = bytes[4] === 2;
-  const little = bytes[5] === 1;
-  const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
-  const word = (at: number) =>
-    Number(wide ? view.getBigUint64(at, little) : view.getUint32(at, little));
-  const table = word(wide ? 40 : 32);
-  const width = wide ? 64 : 40;
-  const section = table + sectionIndex * width;
-  const offset = word(section + (wide ? 24 : 16));
-  const size = word(section + (wide ? 32 : 20));
-  const header = Buffer.alloc(wide ? 24 : 12);
-  const chdr = new DataView(
-    header.buffer,
-    header.byteOffset,
-    header.byteLength,
-  );
-  chdr.setUint32(0, 1, little); // ELFCOMPRESS_ZLIB
-  if (wide) {
-    chdr.setBigUint64(8, BigInt(size), little);
-    chdr.setBigUint64(16, 1n, little);
-  } else {
-    chdr.setUint32(4, size, little);
-    chdr.setUint32(8, 1, little);
-  }
-  const storage = Buffer.concat([
-    header,
-    deflateSync(bytes.subarray(offset, offset + size)),
-  ]);
-  const count = view.getUint16(wide ? 60 : 48, little);
-  const result = Buffer.concat([
-    bytes,
-    Buffer.alloc(versionStrings ? width : 0),
-    storage,
-  ]);
-  const updated = new DataView(
-    result.buffer,
-    result.byteOffset,
-    result.byteLength,
-  );
-  const setWord = (at: number, value: number) =>
-    wide
-      ? updated.setBigUint64(at, BigInt(value), little)
-      : updated.setUint32(at, value, little);
-  const target = versionStrings ? table + count * width : section;
-  if (versionStrings) {
-    bytes.copy(result, target, section, section + width);
-    updated.setUint16(wide ? 60 : 48, count + 1, little);
-    // Definitions and requirements use the copied string table; dynsym keeps
-    // its original uncompressed table and still supplies trustworthy names.
-    for (const index of [4, 5])
-      updated.setUint32(
-        table + index * width + (wide ? 40 : 24),
-        count,
-        little,
-      );
-  }
-  setWord(target + 8, 0x800); // SHF_COMPRESSED, without SHF_ALLOC
-  setWord(
-    target + (wide ? 24 : 16),
-    bytes.length + (versionStrings ? width : 0),
-  );
-  setWord(target + (wide ? 32 : 20), storage.length);
-  return result;
-};
-
-it.each(
-  ([32, 64] as const).flatMap((bits) =>
-    (
-      [
-        "symbols",
-        "strings",
-        "indices",
-        "definitions",
-        "requirements",
-        "version-strings",
-      ] as const
-    ).map((kind) => ({ bits, kind })),
-  ),
-)(
-  "keeps compressed ELF$bits $kind distinct from logical table bytes",
-  ({ bits, kind }) => {
-    for (const little of [false, true]) {
-      const bytes = elfExportImage({
-        bits,
-        little,
-        symbols: [
-          { name: "defined", version: 2 },
-          { name: "required", version: 3 },
-        ],
-        versionDefinitions: ["lib.so", "DEFINED"],
-        versionRequirements: [{ index: 3, name: "REQUIRED" }],
-      });
-      expect(parse(bytes)).toMatchObject({
-        coverage: { status: "complete", exports: 2 },
-      });
-      const index = {
-        symbols: 1,
-        strings: 2,
-        indices: 3,
-        definitions: 4,
-        requirements: 5,
-        "version-strings": 2,
-      }[kind];
-      const result = parse(
-        compressExportSection(bytes, index, kind === "version-strings"),
-      );
-      if (kind === "symbols" || kind === "strings") {
-        expect(result).toMatchObject({
-          exports: [],
-          coverage: {
-            status: "unsupported",
-            examined_entries: 0,
-            reason: expect.stringContaining("SHF_COMPRESSED"),
-          },
-        });
-      } else {
-        expect(result).toMatchObject({
-          coverage: { status: "partial", exports: 2 },
-          exports: [
-            {
-              name: "defined",
-              version:
-                kind === "indices"
-                  ? "unknown"
-                  : {
-                      index: 2,
-                      name:
-                        kind === "definitions" || kind === "version-strings"
-                          ? null
-                          : "DEFINED",
-                    },
-            },
-            {
-              name: "required",
-              version:
-                kind === "indices"
-                  ? "unknown"
-                  : {
-                      index: 3,
-                      name:
-                        kind === "definitions" ||
-                        kind === "requirements" ||
-                        kind === "version-strings"
-                          ? null
-                          : "REQUIRED",
-                    },
-            },
-          ],
-        });
-        expect(result.issues).toContainEqual(
-          expect.objectContaining({
-            code: "version_unresolved",
-            message: expect.stringContaining("SHF_COMPRESSED"),
-          }),
-        );
-      }
-    }
-  },
-);
-
 it.each(["requirements", "definitions"] as const)(
   "bounds aliased GNU version %s work and keeps exports with unknown versions",
   (kind) => {
@@ -873,12 +706,13 @@ describe("ELF version requirements", () => {
   });
 
   it("uses a definition name when a requirement shares its index", () => {
-    const bytes = elfExportImage({
-      symbols: [{ name: "ambiguous", version: 2 }],
-      versionDefinitions: ["libfixture.so", "DEFINITION"],
-      versionRequirements: [{ index: 2, name: "REQUIREMENT" }],
-    });
-    const result = parse(bytes);
+    const result = parse(
+      elfExportImage({
+        symbols: [{ name: "ambiguous", version: 2 }],
+        versionDefinitions: ["libfixture.so", "DEFINITION"],
+        versionRequirements: [{ index: 2, name: "REQUIREMENT" }],
+      }),
+    );
 
     expect(result.exports).toMatchObject([
       {
@@ -888,10 +722,6 @@ describe("ELF version requirements", () => {
     ]);
     expect(result.coverage.status).toBe("complete");
     expect(result.issues).toEqual([]);
-    expect(parse(compressExportSection(bytes, 4))).toMatchObject({
-      exports: [{ name: "ambiguous", version: { index: 2, name: null } }],
-      coverage: { status: "partial" },
-    });
   });
 
   it("retains exports and reports a truncated version-requirement chain", () => {

src/native/exports/NativeExportParser.ts

@@ -294,22 +294,12 @@ const versionSectionData = (
   table: { readonly offset: number; readonly size: number };
   names: Buffer;
 } => {
-  if (section.compressed)
-    throw new BinaryFormatFailure(
-      "unsupported",
-      `${label} are SHF_COMPRESSED and were not decompressed`,
-    );
   const strings = sections[section.link];
   if (strings?.type !== SHT_STRTAB)
     throw new BinaryFormatFailure(
       "malformed",
       `${label} do not link to a string table`,
     );
-  if (strings.compressed)
-    throw new BinaryFormatFailure(
-      "unsupported",
-      `${label} strings are SHF_COMPRESSED and were not decompressed`,
-    );
   const stringRange = reader.fileRange(
     strings.offset,
     strings.size,
@@ -555,13 +545,7 @@ function* readVersionNames(
         }
       }
     } catch (cause) {
-      // An unread compressed definition table may replace any requirement
-      // index. Its absence cannot justify falling back to requirement names.
-      if (
-        cause instanceof ElfVersionWorkFailure ||
-        (cause instanceof BinaryFormatFailure && cause.kind === "unsupported")
-      )
-        namesByIndex.clear();
+      if (cause instanceof ElfVersionWorkFailure) namesByIndex.clear();
       issues.push({
         code: "version_unresolved",
         location: hex(verdef.offset),
@@ -621,32 +605,6 @@ function* parseElfExports(
     };
   const width = directory.bits === 64 ? 24 : 16;
   const strings = sections[dynsym.link];
-  const compressed = dynsym.compressed
-    ? dynsym
-    : strings?.type === SHT_STRTAB && strings.compressed
-      ? strings
-      : null;
-  if (compressed !== null) {
-    const reason = `The ELF ${compressed === dynsym ? "dynamic symbol table" : "dynamic string table"} is SHF_COMPRESSED and was not decompressed; export identities remain unknown`;
-    return {
-      ...result,
-      exports: [],
-      coverage: {
-        status: "unsupported",
-        reason,
-        examined_entries: 0,
-        exports: 0,
-      },
-      issues: [
-        {
-          code: "table_unavailable",
-          location: hex(compressed.offset),
-          message: reason,
-        },
-      ],
-      limitations: ELF_LIMITATIONS,
-    };
-  }
   if (
     dynsym.entry_size !== BigInt(width) ||
     dynsym.size % BigInt(width) !== 0n ||
@@ -689,11 +647,6 @@ function* parseElfExports(
   let versions: number | null = null;
   if (versym !== undefined) {
     try {
-      if (versym.compressed)
-        throw new BinaryFormatFailure(
-          "unsupported",
-          "ELF symbol versions are SHF_COMPRESSED and were not decompressed",
-        );
       if (versym.size !== BigInt(count * 2))
         throw new BinaryFormatFailure(
           "malformed",

src/native/hardening/BinaryHardeningParsers.test.ts

@@ -1405,40 +1405,13 @@ it("sizes an empty DT_GNU_HASH table only from an agreeing SHT_DYNSYM", () => {
     strings.readBigUInt64LE(elfSectionAt(strings, SHT_STRTAB) + 32) - 1n,
     elfSectionAt(strings, SHT_STRTAB) + 32,
   );
-  const compressedSymbols = Buffer.from(agreeing);
-  compressedSymbols.writeBigUInt64LE(0x800n, section + 8);
-  const compressedStrings = Buffer.from(agreeing);
-  compressedStrings.writeBigUInt64LE(
-    0x800n,
-    elfSectionAt(compressedStrings, SHT_STRTAB) + 8,
-  );
-  const wrongStringType = Buffer.from(agreeing);
-  wrongStringType.writeUInt32LE(
-    1,
-    elfSectionAt(wrongStringType, SHT_STRTAB) + 4,
-  );
-  for (const bytes of [
-    moved,
-    offset,
-    strings,
-    compressedSymbols,
-    compressedStrings,
-    wrongStringType,
-  ])
+  for (const bytes of [moved, offset, strings])
     expect(
       findRow(readElfHardening(bytes).rows, "stack_protector"),
     ).toMatchObject({
       state: "unknown",
       note: expect.stringContaining("DT_GNU_HASH"),
     });
-  // A loader-owned hash count needs no section fallback, so compressed section
-  // declarations cannot hide imports named by DT_SYMTAB and DT_STRTAB.
-  const hashed = elfHardeningFixture({ stackChk: true });
-  for (const type of [SHT_DYNSYM, SHT_STRTAB])
-    hashed.writeBigUInt64LE(0x800n, elfSectionAt(hashed, type) + 8);
-  expect(findRow(readElfHardening(hashed).rows, "stack_protector").state).toBe(
-    "enabled",
-  );
 });
 
 it("keeps an unresolved symbol count distinct from an absent table", () => {

src/native/hardening/ElfHardening.ts

@@ -51,7 +51,6 @@ import {
 const ET_EXEC = 2;
 const ET_DYN = 3;
 const SHT_SYMTAB = 2;
-const SHT_STRTAB = 3;
 const SHT_NOTE = 7;
 const SHT_DYNSYM = 11;
 const DT_NULL = 0n;
@@ -72,6 +71,7 @@ const DF_1_PIE = 0x08000000n;
 const PF_X = 1;
 const GNU_PROPERTY_AARCH64_FEATURE_1_AND = 0xc0000000;
 const GNU_PROPERTY_X86_FEATURE_1_AND = 0xc0000002;
+const SHF_COMPRESSED = 0x800n;
 /** Tags hardening reads as a single value. Repeating tags such as DT_NEEDED stay. */
 const SINGULAR_DYNAMIC_TAGS = new Set<bigint>([
   DT_HASH,
@@ -175,6 +175,7 @@ export const readElfHardening = (
   assertElfDeclaredRangesFromBuffer(bytes);
   const { bits, little, machine, programs, sections } = directory;
   const headerWidth = bits === 64 ? 56 : 32;
+  const symbolWidth = bits === 64 ? 24 : 16;
   const dynamicWidth = bits === 64 ? 16 : 8;
   const propertyAlign = bits === 64 ? 8 : 4;
   const loads = programs.filter(isSpan).filter((program) => program.type === 1);
@@ -545,14 +546,10 @@ const agreeingSectionCount = (
   if (dynsym === undefined) return null;
   const strings = sections[dynsym.link];
   if (
-    dynsym.compressed ||
-    strings === undefined ||
-    strings.compressed ||
-    strings.type !== SHT_STRTAB ||
     dynsym.address !== symtab.value ||
-    strings.address !== dynamic.entries.get(DT_STRTAB)?.value ||
-    strings.size !== dynamic.entries.get(DT_STRSZ)?.value ||
-    strings.offset !== BigInt(dynamic.stringFileOffset ?? -1)
+    strings?.address !== dynamic.entries.get(DT_STRTAB)?.value ||
+    strings?.size !== dynamic.entries.get(DT_STRSZ)?.value ||
+    strings?.offset !== BigInt(dynamic.stringFileOffset ?? -1)
   )
     return null;
   const entry = dynsym.entry_size === 0n ? BigInt(width) : dynsym.entry_size;
@@ -900,10 +897,11 @@ const readFeatureNotes = (
     if (section.type !== SHT_NOTE) continue;
     // An empty note section owns no bytes, so it has nothing to walk.
     if (section.size === 0n) continue;
-    if (section.compressed)
+    const compressed = (section.flags & SHF_COMPRESSED) !== 0n;
+    if (compressed)
       incomplete ??=
         "A compressed SHT_NOTE section may hold GNU property notes, and its descriptors were not read.";
-    if (section.compressed) {
+    if (compressed) {
       if (!section.file_backed) continue;
       otherSpans.push({
         offset: exact(section.offset, "SHT_NOTE offset"),

src/native/initializers/ElfInitializerSymbols.ts

@@ -124,17 +124,11 @@ const stringAt = (
   return { name: text, missing: false };
 };
 
-const stringTableBytes = (
+const tableBytes = (
   bytes: Buffer,
   section: NativeSection | undefined,
 ): Buffer | null => {
-  if (
-    section === undefined ||
-    section.type !== 3 ||
-    !section.file_backed ||
-    section.compressed
-  )
-    return null;
+  if (section === undefined || !section.file_backed) return null;
   const offset = Number(section.offset);
   const size = Number(section.size);
   if (offset < 0 || size < 0 || offset > bytes.length - size) return null;
@@ -150,19 +144,9 @@ const readTable = (
 ): {
   readonly symbols: ElfInitializerSymbol[];
   readonly truncated: boolean;
-  readonly incomplete: boolean;
 } => {
   const width = facts.bits === 64 ? 24 : 16;
-  const strings = stringTableBytes(facts.bytes, sections[section.link]);
-  const compressedStrings = sections[section.link]?.compressed === true;
-  if (compressedStrings)
-    notes.add(
-      "A symbol string table is compressed; its names were not decoded.",
-    );
-  else if (strings === null)
-    notes.add(
-      "A symbol table does not link a readable SHT_STRTAB section; its names were not decoded.",
-    );
+  const strings = tableBytes(facts.bytes, sections[section.link]);
   const start = Number(section.offset);
   const declared = section.size / BigInt(width);
   const count = Number(declared < BigInt(budget) ? declared : BigInt(budget));
@@ -193,7 +177,7 @@ const readTable = (
       type: parsed.value.type,
     });
   }
-  return { symbols, truncated, incomplete: nameMissing || strings === null };
+  return { symbols, truncated: truncated || nameMissing };
 };
 
 /** Load SHT_SYMTAB and SHT_DYNSYM once. Defined STT_FUNC names win ties. */
@@ -239,20 +223,10 @@ export const loadElfSymbolIndex = (
   sections.forEach((section, index) => {
     if (truncated) return;
     if (section.type !== 2 && section.type !== 11) return;
-    if (section.compressed) {
-      notes.add("A symbol table is compressed; its symbols were not decoded.");
-      unreadable = true;
-      return;
-    }
-    const width = BigInt(facts.bits === 64 ? 24 : 16);
-    if (section.entry_size !== 0n && section.entry_size !== width) {
-      notes.add(
-        "A symbol table has an unexpected entry size; its symbols were not decoded.",
-      );
-      unreadable = true;
-      return;
-    }
-    if (!section.file_backed || section.size % width !== 0n) {
+    if (
+      !section.file_backed ||
+      section.size % BigInt(facts.bits === 64 ? 24 : 16) !== 0n
+    ) {
       notes.add(
         "A symbol table is not stored in the file or its size is not a whole number of entries, so its names were not read.",
       );
@@ -263,7 +237,6 @@ export const loadElfSymbolIndex = (
     budget -= table.symbols.length;
     tables.set(index, table.symbols);
     truncated ||= table.truncated;
-    unreadable ||= table.incomplete;
     for (const symbol of table.symbols) consider(symbol);
   });
   return {
@@ -467,11 +440,7 @@ export const sectionRelocations = async (
   for (const [position, section] of input.sections.entries()) {
     const encoding = applicable(input, section);
     if (encoding === null) continue;
-    if (!section.file_backed || section.compressed) {
-      if (section.compressed)
-        input.notes.add(
-          "A relocation section is compressed; its records were not decoded.",
-        );
+    if (!section.file_backed) {
       skip(section);
       continue;
     }

src/native/initializers/ElfInitializers.ts

@@ -269,7 +269,7 @@ const indexSections = (sections: readonly NativeSection[]): ElfSectionIndex => {
           : left.index - right.index,
   );
   const backed = buildAddressRangeIndex(
-    ranges((section) => section.file_backed && !section.compressed),
+    ranges((section) => section.file_backed),
     (left, right) => left.index - right.index,
   );
   return {
@@ -354,8 +354,7 @@ const findSections = (
 const withinSection =
   (section: NativeSection, width: number) =>
   (address: bigint): number | null => {
-    if (!section.file_backed || section.compressed || address < section.address)
-      return null;
+    if (!section.file_backed || address < section.address) return null;
     const delta = address - section.address;
     if (delta + BigInt(width) > section.size) return null;
     return Number(section.offset + delta);
@@ -375,13 +374,6 @@ const sectionSource = (
     section.name.length <= MAX_NATIVE_INITIALIZER_NAME_BYTES
       ? section.name
       : fallbackName;
-  if (section.compressed) {
-    note(
-      scan,
-      `${label} is compressed. Its initializer slots were not decoded.`,
-    );
-    return { kind, sentinel, detail: label, slots: [] };
-  }
   if (!section.file_backed) {
     note(scan, `${label} is not file-backed. Its slots were omitted.`);
     return { kind, sentinel, detail: label, slots: [] };
@@ -679,7 +671,6 @@ const loadWrites = async (
 };
 
 const dynamicSymbols = (
-  scan: ElfScan,
   sections: readonly NativeSection[],
   tags: ReadonlyMap<bigint, DynTag>,
   tables: ReadonlyMap<number, readonly ElfInitializerSymbol[]>,
@@ -692,11 +683,6 @@ const dynamicSymbols = (
         (section.type === 11 || section.type === 2),
     );
     if (match >= 0) return tables.get(match);
-    note(
-      scan,
-      "DT_SYMTAB does not identify a decoded symbol table; dynamic relocation symbols are unresolved.",
-    );
-    return undefined;
   }
   const dynsym = sections.findIndex((section) => section.type === 11);
   return dynsym < 0 ? undefined : tables.get(dynsym);
@@ -1056,7 +1042,7 @@ export const readElfInitializers = async (
     loaded,
     sectionRels.found,
     sectionRels.clobbered,
-    dynamicSymbols(scan, directory.sections, tags, symbols.tables),
+    dynamicSymbols(directory.sections, tags, symbols.tables),
     symbols,
     loaded.trustRaw && sectionRels.complete,
     directory.sections,

src/native/initializers/NativeInitializersParsers.test.ts

@@ -1,5 +1,4 @@
 import { describe, expect, it, vi } from "vitest";
-import { deflateSync } from "node:zlib";
 import { readNativeInitializers } from "./NativeInitializersProvider.js";
 
 /** Pass-through spies on the shared mapping module, so tests can count lookups made from other modules. */
@@ -321,106 +320,6 @@ describe("ELF slot semantics", () => {
   });
 });
 
-describe("ELF section content admission", () => {
-  it("keeps symbol relocations unresolved for a conflicting symbol entry width", async () => {
-    const bytes = elfRelocatableCtors();
-    bytes.writeBigUInt64LE(16n, 0x500 + 4 * 64 + 56);
-    const report = await read(bytes);
-    expect(
-      report.entries.find((entry) => entry.kind === "init_array"),
-    ).toMatchObject({
-      resolution: "unresolved",
-      value_va: null,
-      symbol: null,
-    });
-    expect(report.status).toBe("incomplete");
-    expect(report.limitations.join("\n")).toContain("entry size");
-  });
-
-  it.each([
-    { section: 7, label: "initializer array" },
-    { section: 4, label: "symbol table" },
-    { section: 5, label: "symbol string table" },
-    { section: 8, label: "relocation table" },
-  ])("preserves uncertainty for a compressed $label", async ({ section }) => {
-    const base = elfRelocatableCtors();
-    const at = 0x500 + section * 64;
-    const offset = Number(base.readBigUInt64LE(at + 24));
-    const size = Number(base.readBigUInt64LE(at + 32));
-    const header = Buffer.alloc(24);
-    header.writeUInt32LE(1, 0);
-    header.writeBigUInt64LE(BigInt(size), 8);
-    header.writeBigUInt64LE(1n, 16);
-    const compressed = Buffer.concat([
-      header,
-      deflateSync(base.subarray(offset, offset + size)),
-    ]);
-    const bytes = Buffer.concat([base, compressed]);
-    bytes.writeBigUInt64LE(base.readBigUInt64LE(at + 8) | 0x800n, at + 8);
-    bytes.writeBigUInt64LE(BigInt(base.length), at + 24);
-    bytes.writeBigUInt64LE(BigInt(compressed.length), at + 32);
-    const report = await read(bytes);
-    expect(report.status).toBe("incomplete");
-    expect(report.coverage.total_entries).toBeNull();
-    expect(report.limitations.join("\n")).toContain("compressed");
-    if (section === 7)
-      expect(report.entries.some((entry) => entry.kind === "init_array")).toBe(
-        false,
-      );
-    else {
-      const init = report.entries.find((entry) => entry.kind === "init_array");
-      expect(init).toBeDefined();
-      if (section === 5) expect(init?.symbol).toBeNull();
-      else
-        expect(init).toMatchObject({
-          resolution: "unresolved",
-          value_va: null,
-        });
-    }
-    // The uncompressed fixture remains the working comparison.
-    expect((await read(base)).status).toBe("parsed");
-  });
-
-  it("does not substitute an unrelated dynamic symbol table for DT_SYMTAB", async () => {
-    const bytes = elf64PieInitializers();
-    bytes.writeBigUInt64LE(0x777n, 0x300 + 14 * 16 + 8);
-    const report = await read(bytes);
-    expect(
-      report.entries.find((entry) => entry.slot_va === "0x210"),
-    ).toMatchObject({
-      resolution: "unresolved",
-      symbol: null,
-      value_va: null,
-    });
-    expect(report.status).toBe("incomplete");
-  });
-
-  it.each(["compressed", "not a string table"])(
-    "retains later symbol tables when an earlier name source is %s",
-    async (source) => {
-      const bytes = elf64PieInitializers();
-      // The first (dynamic) symbol table links section 8; its bytes still contain imp_init.
-      if (source === "compressed")
-        bytes.writeBigUInt64LE(0x802n, 0x800 + 8 * 64 + 8);
-      else bytes.writeUInt32LE(1, 0x800 + 8 * 64 + 4);
-      const report = await read(bytes);
-      expect(report.status).toBe("incomplete");
-      expect(
-        report.entries.find((entry) => entry.kind === "init"),
-      ).toMatchObject({
-        symbol: { name: "ctor_a" },
-        value_va: "0x100",
-      });
-      expect(
-        report.entries.find((entry) => entry.slot_va === "0x210"),
-      ).toMatchObject({
-        resolution: "unresolved_import",
-        symbol: null,
-      });
-    },
-  );
-});
-
 describe("ELF incomplete inputs", () => {
   it("reports an unsupported relocation machine as incomplete, not as raw zeros", async () => {
     const bytes = elf64PieInitializers();

src/native/metadata/ElfImage.ts

@@ -68,7 +68,8 @@ export const readElfImage = (
   }
   for (const section of directory.sections) {
     const range = declaredFileRange(bytes.length, section.offset, section.size);
-    const { file_backed, compressed } = section;
+    const file_backed = section.type !== 8 && range.file_backed;
+    const compressed = (section.flags & 0x800n) !== 0n;
     const read_only =
       section.type === 1 &&
       file_backed &&

src/native/metadata/NativeSectionDirectory.test.ts

@@ -2,7 +2,6 @@ import { expect, it } from "vitest";
 import { pe } from "../../domain/binaryTarget.fixture.js";
 import { elfHardeningFixture } from "../hardening/BinaryHardening.fixture.js";
 import { elfUnwindSectionlessFixture } from "../elf/ElfUnwindTables.fixture.js";
-import { compressedElfNoteSectionFixture } from "../elf/ElfNotes.fixture.js";
 import {
   ELF_PT_GNU_EH_FRAME,
   ELF_PT_GNU_RELRO,
@@ -95,35 +94,3 @@ it("retains a confirmed overlapping PE when the COFF record extends past EOF", (
     }),
   );
 });
-
-it.each([
-  [32, true],
-  [32, false],
-  [64, true],
-  [64, false],
-] as const)(
-  "retains ELF%i little=%s compression independently of stored section coverage",
-  (bits, little) => {
-    const bytes = compressedElfNoteSectionFixture(bits, little);
-    const initial = readElfDirectoryFromBuffer(bytes).sections[1]!;
-    expect(initial).toMatchObject({ compressed: true, file_backed: true });
-    expect(readElfDirectoryFromBuffer(bytes).sections[2]).toMatchObject({
-      compressed: false,
-      file_backed: true,
-    });
-    // Compression metadata describes the encoding even if its stored range
-    // subsequently proves incomplete. It must not be inferred from readability.
-    const sizeAt = initial.header_offset + (bits === 64 ? 32 : 20);
-    if (bits === 64) {
-      if (little) bytes.writeBigUInt64LE(BigInt(bytes.length), sizeAt);
-      else bytes.writeBigUInt64BE(BigInt(bytes.length), sizeAt);
-    } else if (little) bytes.writeUInt32LE(bytes.length, sizeAt);
-    else bytes.writeUInt32BE(bytes.length, sizeAt);
-    expect(readElfDirectoryFromBuffer(bytes).sections[1]).toMatchObject({
-      compressed: true,
-      file_backed: false,
-      offset: initial.offset,
-      size: BigInt(bytes.length),
-    });
-  },
-);

src/native/metadata/NativeSectionDirectory.ts

@@ -45,10 +45,7 @@ export interface NativeSection {
   readonly entry_size: bigint;
   /** `sh_addralign` for ELF. PE sections have no note alignment and use 1. */
   readonly alignment: bigint;
-  /** Declared stored bytes are present; compressed bytes are not decoded content. */
   readonly file_backed: boolean;
-  /** ELF SHF_COMPRESSED storage encoding; always false for PE sections. */
-  readonly compressed: boolean;
 }
 /** Program header types retained for load, dynamic, hardening, and unwind consumers. */
 export const ELF_PT_NOTE = 4 as const;
@@ -311,7 +308,6 @@ export function* readElfSectionDirectory(
         alignment: section.alignment,
         file_backed:
           type !== 8 && declaredFileRange(fileSize, offset, size).file_backed,
-        compressed: (section.flags & 0x800n) !== 0n,
       });
     }
   }
@@ -414,7 +410,6 @@ export function* readPeSectionDirectory(
         BigInt(row.offset),
         BigInt(row.size),
       ).file_backed,
-      compressed: false,
     });
   }
   return {