[llvm] [ELF]Add overflow check to ELF note iterator (PR #160451)

[Ruoyu Qiu via llvm-commits]

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@@ -310,3 +314,69 @@ TEST(ELFTest, Hash) {
   // presuming 32-bit long. Thus make sure that extra bit doesn't appear. 
   EXPECT_EQ(hashSysV("ZZZZZW9p"), 0U);
 }
+
+template <class ELFT>
+static Expected<ELFObjectFile<ELFT>> toBinary(SmallVectorImpl<char> &Storage,
+                                              StringRef Yaml) {
+  raw_svector_ostream OS(Storage);
+  yaml::Input YIn(Yaml);
+  if (!yaml::convertYAML(YIn, OS, [](const Twine &Msg) {}))
+    return createStringError(std::errc::invalid_argument,
+                             "unable to convert YAML");
+  return ELFObjectFile<ELFT>::create(MemoryBufferRef(OS.str(), "dummyELF"));
+}
+
+TEST(ELFObjectFileTest, ELFNoteIteratorOverflow) {
+  SmallString<0> Storage;
+  Expected<ELFObjectFile<ELF64LE>> ElfOrErr = toBinary<ELF64LE>(Storage, R"(
+--- !ELF
+FileHeader:
+  Class:          ELFCLASS64
+  Data:           ELFDATA2LSB
+  Type:           ET_EXEC
+  Machine:        EM_X86_64
+ProgramHeaders:
+  - Type:         PT_NOTE
+    FileSize:     0xffffffffffffff88
+    FirstSec:     .note.gnu.build-id
+    LastSec:      .note.gnu.build-id
+
+Sections:
+  - Name:         .note.gnu.build-id
+    Type:         SHT_NOTE
+    AddressAlign: 0x04
+    ShOffset:     0xffffffffffffff88
+    Notes:
+      - Name:     "GNU"
+        Desc:     "abb50d82b6bdc861"
+        Type:     3
+)");
+  ASSERT_THAT_EXPECTED(ElfOrErr, Succeeded());
+  ELFFile<ELF64LE> Obj = ElfOrErr.get().getELFFile();
+
+  auto CheckOverflow = [&](auto &&PhdrOrShdr, uint64_t Offset, uint64_t Size) {
+    Error Err = Error::success();
+    Obj.notes(PhdrOrShdr, Err);
+
+    std::string ErrMessage;
+    handleAllErrors(std::move(Err), [&](const ErrorInfoBase &EI) {
+      ErrMessage = EI.message();
+    });
+
+    EXPECT_EQ(ErrMessage, ("invalid offset (0x" + Twine::utohexstr(Offset) +
+                           ") or size (0x" + Twine::utohexstr(Size) + ")")
+                              .str());
+  };
+
+  auto PhdrsOrErr = Obj.program_headers();
----------------
cabbaken wrote:

The type of `PhdrsOrErr` is `Expected<ELFFile<ELF64LE>::Elf_Phdr_Range>`, which is a bit verbose here. Since the `getBuildID` code uses `auto`, I followed the same style.
I can adjust this if needed.

https://github.com/llvm/llvm-project/pull/160451