golang/go · error

symbol %s: section number %d is larger than max %d

Error message

symbol %s: section number %d is larger than max %d

What it means

In `findPESymbol`, after validating that `SectionNumber > 0`, the code checks that it does not exceed the actual number of sections in the PE file (`len(f.Sections)`). If the symbol references a section number beyond the section table's bounds, this error fires. It indicates a corrupt PE symbol table where section indices are inconsistent with the section header table.

Source

Thrown at src/cmd/internal/objfile/pe.go:162

	sect := f.pe.Section(".text")
	if sect == nil {
		return 0, nil, fmt.Errorf("text section not found")
	}
	textStart = imageBase + uint64(sect.VirtualAddress)
	text, err = sect.Data()
	return
}

func findPESymbol(f *pe.File, name string) (*pe.Symbol, error) {
	for _, s := range f.Symbols {
		if s.Name != name {
			continue
		}
		if s.SectionNumber <= 0 {
			return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber)
		}
		if len(f.Sections) < int(s.SectionNumber) {
			return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections))
		}
		return s, nil
	}
	return nil, fmt.Errorf("no %s symbol found", name)
}

func loadPETable(f *pe.File, sname, ename string) ([]byte, error) {
	ssym, err := findPESymbol(f, sname)
	if err != nil {
		return nil, err
	}
	esym, err := findPESymbol(f, ename)
	if err != nil {
		return nil, err
	}
	if ssym.SectionNumber != esym.SectionNumber {
		return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename)
	}

View on GitHub (pinned to b6b368adc5)

Solutions

  1. Verify PE structural integrity with `dumpbin /headers` or a PE analysis tool — check section count consistency.
  2. Rebuild the binary from source with a reliable linker.
  3. If doing malware analysis, handle the error as expected behavior for malformed PEs.
  4. Re-download the binary if it was transferred over an unreliable channel.

Example fix

// before — corrupt PE with inconsistent section indices
f, err := objfile.Open("malformed.exe")
_, err := findPESymbol(f.pe, "runtime.pclntab")  // fails: section number > max

// after — rebuild from source
$ go build -o app.exe ./...
f, err := objfile.Open("app.exe")  // succeeds
Defensive patterns

Strategy: validation

Validate before calling

// Validate section count consistency in PE
func validatePESectionConsistency(path string) error {
    f, err := pe.Open(path)
    if err != nil { return err }
    defer f.Close()
    for _, s := range f.Symbols {
        if s.SectionNumber > 0 && int(s.SectionNumber) > len(f.Sections) {
            return fmt.Errorf("corrupt PE: symbol %s references nonexistent section %d", s.Name, s.SectionNumber)
        }
    }
    return nil
}

Try / catch

sym, err := findPESymbol(pe, name)
if err != nil && strings.Contains(err.Error(), "larger than max") {
    return fmt.Errorf("corrupt PE binary — section/symbol table inconsistency: %w", err)
}

Prevention

When it happens

Trigger: Calling `findPESymbol` on a PE binary where a symbol's `SectionNumber` is larger than the number of sections declared in the PE section header table. This is a structural inconsistency typical of corrupt binaries, PE files produced by buggy tools, or binaries that were manually edited.

Common situations: Analyzing a corrupt Windows binary. Using a PE file that was truncated (section headers removed but symbol table not updated). Binary post-processing tools that modify section counts without updating symbol references. Malware analysis where the PE was deliberately malformed.

Related errors

AI-assisted analysis of golang/go@b6b368adc5 (2026-08-12). Data as JSON: /api/errors/be605e0301cbeb69. Report an issue: GitHub.