Here's an extremely rudimentary naive fuzzer for combine_pdf :
```ruby
#!/usr/bin/env ruby
####################################################
# ------------------------------------------------ #
# Fuzz combine_pdf Ruby gem with mutated PDF files #
# ------------------------------------------------ #
# #
# Each test case is written to 'fuzz.pdf' in the #
# current working directory. #
# #
# Crashes and the associated backtrace are saved #
# in the 'crashes' directory in the current #
# working directory. #
# #
####################################################
# ~ bcoles
require 'date'
require 'combine_pdf'
require 'colorize'
require 'fileutils'
require 'timeout'
require 'securerandom'
VERBOSE = false
OUTPUT_DIR = "#{Dir.pwd}/crashes".freeze
#
# Show usage
#
def usage
puts 'Usage: ./fuzz.rb [FILE2] [FILE3] [...]'
puts 'Example: ./tools/fuzz.rb pdfs/**.pdf'
exit 1
end
#
# Print status message
#
# @param [String] msg message to print
#
def print_status(msg = '')
puts '[*] '.blue + msg if VERBOSE
end
#
# Print progress messages
#
# @param [String] msg message to print
#
def print_good(msg = '')
puts '[+] '.green + msg if VERBOSE
end
#
# Print error message
#
# @param [String] msg message to print
#
def print_error(msg = '')
puts '[-] '.red + msg
end
#
# Setup environment
#
def setup
FileUtils.mkdir_p OUTPUT_DIR unless File.directory? OUTPUT_DIR
rescue => e
print_error "Could not create output directory '#{OUTPUT_DIR}': #{e}"
exit 1
end
#
# Generate a mutated PDF file with a single mitated byte
#
# @param [Path] f path to PDF file
#
def mutate_byte(f)
data = IO.binread f
position = SecureRandom.random_number data.size
new_byte = SecureRandom.random_number 256
new_data = data.dup.tap { |s| s.setbyte(position, new_byte) }
File.open(@fuzz_outfile, 'w') do |file|
file.write new_data
end
end
#
# Generate a mutated PDF file with multiple mutated bytes
#
# @param [Path] f path to PDF file
#
def mutate_bytes(f)
data = IO.binread f
fuzz_factor = 200
num_writes = rand((data.size / fuzz_factor.to_f).ceil) + 1
new_data = data.dup
num_writes.times do
position = SecureRandom.random_number data.size
new_byte = SecureRandom.random_number 256
new_data.tap { |stream| stream.setbyte position, new_byte }
end
File.open(@fuzz_outfile, 'w') do |file|
file.write new_data
end
end
#
# Generate a mutated PDF file with all integers replaced by '-1'
#
# @param [Path] f path to PDF file
#
def clobber_integers(f)
data = IO.binread f
new_data = data.dup.gsub(/\d/, '-1')
File.open(@fuzz_outfile, 'w') do |file|
file.write new_data
end
end
#
# Generate a mutated PDF file with all strings 3 characters or longer
# replaced with 2000 'A' characters
#
# @param [Path] f path to PDF file
#
def clobber_strings(f)
data = IO.binread(f)
new_data = data.dup.gsub(/[a-zA-Z]{3,}/, 'A' * 2000)
File.open(@fuzz_outfile, 'w') do |file|
file.write new_data
end
end
#
# Read a PDF file
#
# @param [String] f path to PDF file
#
def read(f)
print_status "Processing '#{f}'"
begin
pdf = CombinePDF.new
pdf << CombinePDF.load(f)
rescue CombinePDF::ParsingError
print_status "Could not parse PDF '#{f}': PDF is malformed"
return
end
print_good 'Processing complete'
print_status "Parsing '#{f}'"
begin
parse(pdf)
rescue CombinePDF::ParsingError
print_status "Could not parse PDF '#{f}': PDF is malformed"
return
end
print_good 'Parsing complete'
end
#
# Parse PDF
#
# @param [CombinePDF::PDF] pdf CombinePDF PDF
#
def parse(pdf)
print_status 'Parsing PDF contents...'
pdf.title
pdf.author
pdf.clear_forms_data
pdf.outlines
pdf.forms_data
contents = ''
pdf.pages.each do |page|
contents << page.secure_injection.to_s
contents << page.make_secure.to_s
contents << page.make_unsecure.to_s
contents << page.mediabox.to_s
contents << page.cropbox.to_s
contents << page.page_size.to_s
contents << page.resources.to_s
contents << page.fix_rotation.to_s
contents << page.rotate_left.to_s
contents << page.rotate_right.to_s
contents << page.rotate_180.to_s
end
# puts contents if VERBOSE
end
#
# Show summary of crashes
#
def summary
puts
puts "Complete! Crashes saved to '#{OUTPUT_DIR}'"
puts
puts `/usr/bin/head -n1 #{OUTPUT_DIR}/*.trace` if File.exist? '/usr/bin/head'
end
#
# Report error message to STDOUT
# and save fuzz test case and backtrace to OUTPUT_DIR
#
def report_crash(e)
puts " - #{e.message}"
puts e.backtrace.first
fname = "#{DateTime.now.strftime('%Y%m%d%H%M%S%N')}_crash_#{rand(1000)}"
FileUtils.mv @fuzz_outfile, "#{OUTPUT_DIR}/#{fname}.pdf"
File.open("#{OUTPUT_DIR}/#{fname}.pdf.trace", 'w') do |file|
file.write "#{e.message}\n#{e.backtrace.join "\n"}"
end
end
#
# Test combine_pdf with the mutated file
#
def test
Timeout.timeout(@timeout) do
read(@fuzz_outfile)
end
rescue SystemStackError => e
report_crash e
rescue Timeout::Error => e
report_crash e
rescue SyntaxError => e
report_crash e
rescue => e
raise e unless e.backtrace.join("\n") =~ %r{combine_pdf}
report_crash e
end
#
# Generate random byte mutations and run test
#
# @param [String] f path to PDF file
#
def fuzz_bytes(f)
iterations = 1000
1.upto(iterations) do |i|
print "\r#{(i * 100) / iterations} % (#{i} / #{iterations})"
mutate_bytes f
test
end
end
#
# Generate integer mutations and run tests
#
# @param [String] f path to PDF file
#
def fuzz_integers(f)
clobber_integers f
test
end
#
# Generate string mutations and run tests
#
# @param [String] f path to PDF file
#
def fuzz_strings(f)
clobber_strings f
test
end
puts '-' * 60
puts '% Fuzzer for combine_pdf Ruby gem'
puts '-' * 60
puts
usage if ARGV[0].nil?
setup
@timeout = 15
@fuzz_outfile = 'fuzz.pdf'
trap 'SIGINT' do
puts
puts 'Caught interrupt. Exiting...'
summary
exit 130
end
ARGV.each do |f|
unless File.exist? f
print_error "Could not find file '#{f}'"
next
end
fuzz_integers f
fuzz_strings f
fuzz_bytes f
puts '-' * 60
end
summary
```
```
$ head -n 2 crashes/*.trace
==> crashes/20220426190213126745428_crash_341.pdf.trace <==
no implicit conversion of Symbol into String
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `+'
==> crashes/20220426190214152951768_crash_426.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426190214341671486_crash_713.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426190214444052741_crash_0.pdf.trace <==
:"0" can't be coerced into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `+'
==> crashes/20220426190214686444966_crash_492.pdf.trace <==
undefined method `-' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426190214912506425_crash_295.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426190214929390431_crash_50.pdf.trace <==
Hash can't be coerced into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `+'
==> crashes/20220426190215090244659_crash_427.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426190215105336924_crash_372.pdf.trace <==
undefined method `-' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426190215147813391_crash_559.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426190215416139804_crash_429.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426190531857239929_crash_477.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426190554714405144_crash_138.pdf.trace <==
undefined method `+' for :"FontDescriptor\x9940":Symbol
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426190558573380373_crash_73.pdf.trace <==
undefined method `+' for #
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426190702288408271_crash_774.pdf.trace <==
stack level too deep
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:734:in `merge'
==> crashes/20220426190719754023238_crash_578.pdf.trace <==
execution expired
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:502:in `[]'
==> crashes/20220426190751044259444_crash_793.pdf.trace <==
stack level too deep
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:734:in `merge'
==> crashes/20220426190753386086549_crash_953.pdf.trace <==
stack level too deep
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:734:in `merge'
==> crashes/20220426190943542034142_crash_631.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:575:in `[]'
==> crashes/20220426190946206240531_crash_649.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:575:in `[]'
==> crashes/20220426191024127412409_crash_29.pdf.trace <==
undefined method `+' for #
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426191101101780932_crash_17.pdf.trace <==
undefined method `+' for :"9":Symbol
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426191235923098521_crash_215.pdf.trace <==
stack level too deep
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:605:in `extend'
==> crashes/20220426191258777032784_crash_215.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426191348660561350_crash_152.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426191352043419716_crash_195.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426191501709339569_crash_539.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426191631706620420_crash_536.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426191952999847269_crash_914.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426191953043258198_crash_77.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426191953401475229_crash_552.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:611:in `[]'
==> crashes/20220426191954146910314_crash_832.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:611:in `[]'
==> crashes/20220426191954195017865_crash_185.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `catalog_pages'
==> crashes/20220426191957466192534_crash_503.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426191958128974966_crash_491.pdf.trace <==
index out of range
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:364:in `pos='
==> crashes/20220426192003938396027_crash_41.pdf.trace <==
undefined method `+' for :Transparency:Symbol
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426192017172559341_crash_304.pdf.trace <==
undefined method `-' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426192019509123235_crash_540.pdf.trace <==
undefined method `+' for :Contents:Symbol
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426192125042179274_crash_665.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192209935262224_crash_14.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192214498144605_crash_7.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192214834927659_crash_115.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192219431382268_crash_804.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192223570456406_crash_228.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192240164626689_crash_422.pdf.trace <==
execution expired
./fuzz.rb:189:in `inspect'
==> crashes/20220426192240709780793_crash_810.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192257040452835_crash_366.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192300328968226_crash_996.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192302948775686_crash_589.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192323370389407_crash_463.pdf.trace <==
execution expired
./fuzz.rb:184:in `inspect'
==> crashes/20220426192324352526925_crash_928.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192349055110530_crash_576.pdf.trace <==
execution expired
./fuzz.rb:184:in `inspect'
==> crashes/20220426192355993303935_crash_185.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192358893611003_crash_680.pdf.trace <==
undefined method `between?' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:324:in `_parse_'
==> crashes/20220426192418348259575_crash_757.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192418370476584_crash_699.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426192418567253927_crash_720.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192418642321257_crash_843.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426192419091152694_crash_279.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426192419173649475_crash_711.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192419191502533_crash_849.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192420953526663_crash_852.pdf.trace <==
index out of range
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:364:in `pos='
==> crashes/20220426192423650748606_crash_802.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192425018620560_crash_298.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
==> crashes/20220426192425695795473_crash_566.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192426163078824_crash_706.pdf.trace <==
undefined method `+' for :Info:Symbol
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426192427120775205_crash_704.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192427658877498_crash_555.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:545:in `[]'
==> crashes/20220426192435353532689_crash_614.pdf.trace <==
undefined method `+' for :Pages:Symbol
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:662:in `block in serialize_objects_and_references'
==> crashes/20220426192435734418271_crash_600.pdf.trace <==
undefined method `-' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426192436018053493_crash_607.pdf.trace <==
undefined method `-' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426192436801062893_crash_935.pdf.trace <==
undefined method `-' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426192437095870739_crash_745.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:145:in `[]'
==> crashes/20220426192437183910820_crash_55.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192454586411051_crash_136.pdf.trace <==
undefined method `-' for nil:NilClass
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426192454640819965_crash_76.pdf.trace <==
undefined method `-' for :"792":Symbol
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/page_methods.rb:412:in `fix_rotation'
==> crashes/20220426192454717376548_crash_542.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192455414974113_crash_386.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192455597037997_crash_759.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:513:in `[]'
==> crashes/20220426192455674158577_crash_32.pdf.trace <==
no implicit conversion of Symbol into Integer
/var/lib/gems/2.7.0/gems/combine_pdf-1.0.22/lib/combine_pdf/parser.rb:186:in `[]'
```
Unique crash messages:
$ head -n 1 crashes/*.trace | fgrep -v "==>" | sort -u
:"0" can't be coerced into Integer
execution expired
Hash can't be coerced into Integer
index out of range
no implicit conversion of Symbol into Integer
no implicit conversion of Symbol into String
stack level too deep
undefined method `between?' for nil:NilClass
undefined method `-' for :"792":Symbol
undefined method `+' for :"9":Symbol
undefined method `+' for :Contents:Symbol
undefined method `+' for :"FontDescriptor\x9940":Symbol
undefined method `+' for #<Hash:0x000056265af07658>
undefined method `+' for #<Hash:0x000056265b040fd8>
undefined method `+' for :Info:Symbol
undefined method `-' for nil:NilClass
undefined method `+' for :Pages:Symbol
undefined method `+' for :Transparency:Symbol
Here's an extremely rudimentary naive fuzzer for
combine_pdf:Here's the stack traces for the latest version on
masterusing test data from pdf-reader as input.crashes.zip
Summary:
Unique crash messages:
Unique crash locations: