fix(crash-reporting): stop discarding the whole module list on POSIX dumps (#16687)

src/main/crash-reporting/minidump-crash-signature.test.ts

@@ -194,6 +194,22 @@ function buildDump(options: {
   return { dump: builder.build(streams) }
 }
 
+/** Offset of a stream's directory entry: `{type, size, rva}`. */
+function streamEntry(dump: Buffer, type: number): number {
+  const directoryRva = dump.readUInt32LE(12)
+  for (let index = 0; index < dump.readUInt32LE(8); index += 1) {
+    const entry = directoryRva + index * 12
+    if (dump.readUInt32LE(entry) === type) {
+      return entry
+    }
+  }
+  throw new Error(`no stream of type ${type}`)
+}
+
+function moduleListRva(dump: Buffer): number {
+  return dump.readUInt32LE(streamEntry(dump, STREAM_TYPE_MODULE_LIST) + 8)
+}
+
 const FATAL_LINE =
   '[8104:1234:0815/143022.123456:FATAL:render_frame_impl.cc(4821)] Check failed: !is_detached_.'
 
@@ -340,6 +356,37 @@ describe('parseMinidumpCrashSignature', () => {
     expect(signature?.faultingModuleOffset).toBe('0x1234')
   })
 
+  it('resolves a faulting module past index 1024 on a real macOS image count', () => {
+    // A measured macOS renderer carries 1042 loaded images; a cap below that
+    // dropped the whole module list, so no macOS report could name a module.
+    const modules = Array.from({ length: 1042 }, (_, index) => ({
+      base: 0x1_0000_0000n + BigInt(index) * 0x1_0000n,
+      size: 0x1000,
+      name: `/Applications/Orca.app/Contents/Frameworks/lib${index}.dylib`
+    }))
+    const { dump } = buildDump({
+      exception: { code: 11, address: 0x1_0000_0000n + 1030n * 0x1_0000n + 0x24n },
+      modules
+    })
+
+    const signature = parseMinidumpCrashSignature(dump)
+
+    expect(signature?.faultingModule).toBe('lib1030.dylib')
+    expect(signature?.faultingModuleOffset).toBe('0x24')
+  })
+
+  it('still drops the module list when the claimed module count is absurd', () => {
+    const { dump } = buildDump({
+      exception: { code: 11, address: 0x7ff7_0000_0010n },
+      modules: [{ base: 0x7ff7_0000_0000n, size: 0x1000, name: '/opt/orca/orca' }]
+    })
+    const corrupt = Buffer.from(dump)
+    corrupt.writeUInt32LE(0xffff_ffff, moduleListRva(corrupt))
+
+    expect(() => parseMinidumpCrashSignature(corrupt)).not.toThrow()
+    expect(parseMinidumpCrashSignature(corrupt)?.faultingModule).toBeUndefined()
+  })
+
   it('omits the faulting module when no image range covers the address', () => {
     const { dump } = buildDump({
       exception: { code: 11, address: 0x10n },

src/main/crash-reporting/minidump-crash-signature.ts

@@ -11,13 +11,16 @@
 // rather than throwing: a truncated dump must degrade, not break crash
 // reporting.
 
-import { findStream, isMinidump, MAX_MODULES, MinidumpView } from './minidump-stream-reader'
+import { findStream, isMinidump, MinidumpView } from './minidump-stream-reader'
 import { readCrashpadAnnotations } from './minidump-crashpad-annotations'
 
 const STREAM_TYPE_MODULE_LIST = 4
 const STREAM_TYPE_EXCEPTION = 6
 
 const MODULE_RECORD_SIZE = 108
+// 8x headroom over a measured 1042-image macOS renderer, whose whole list a
+// 1_024 cap dropped; a dump claiming more than this is corrupt.
+const MAX_MODULE_LIST_MODULES = 8_192
 const MODULE_BASE_OFFSET = 0
 const MODULE_SIZE_OFFSET = 8
 const MODULE_NAME_RVA_OFFSET = 20
@@ -70,7 +73,7 @@ function readModules(view: MinidumpView): ModuleRecord[] {
     return []
   }
   const count = view.u32(stream.rva)
-  if (count === null || count > MAX_MODULES) {
+  if (count === null || count > MAX_MODULE_LIST_MODULES) {
     return []
   }
   const modules: ModuleRecord[] = []

src/main/crash-reporting/minidump-stream-reader.ts

@@ -13,7 +13,7 @@ const DIRECTORY_ENTRY_SIZE = 12
 // A dump claiming an absurd stream count is corrupt; cap before iterating.
 const MAX_STREAMS = 4_096
 export const MAX_ANNOTATION_VALUE_BYTES = 8_192
-// Shared cap: both the MINIDUMP_MODULE_LIST and Crashpad's per-module info list.
+// Cap for Crashpad's per-module info list; the MINIDUMP_MODULE_LIST is capped separately.
 export const MAX_MODULES = 1_024
 
 export type LocationDescriptor = {