Uncaught MemoryError, OverflowError, ValueError in CONCAT

[sam-xif]

Summary of the problem

Hello manticore community,

I am working as part of a research team developing a code analysis tool for Python. One of the issues the tool discovered in manticore's codebase is that core.smtlib.operators.CONCAT has the potential to throw uncaught MemoryError, OverflowError, and ValueError. These errors are caused by very large, or negative, values for the arg_size argument.

If you are interested in learning more about the tool and how it found this issue, let me know down in the comments, or you can contact me at [email protected]. We are primarily curious about whether you find that this issue is legitimate and worth reporting and fixing. If not, we would be interested in understanding why.

Thank you for your consideration!

-Sam

Manticore version

Latest master (commit hash: 8861005)

Python version

Python 3.8

OS / Environment

Linux (kernel version 5.10.218)

Dependencies

N/A

Step to reproduce the behavior

Call CONCAT with a large value, or negative value, for the arg_size argument.

Expected behavior

Magnitude of size is appropriately limited, perhaps with an assertion.

Actual behavior

Traceback:

Traceback (most recent call last):
  ...
  File ".../repos/manticore/manticore/core/smtlib/operators.py", line 172, in CONCAT
    result = (result << arg_size) | (arg & ((1 << arg_size) - 1))
OverflowError: too many digits in integer

Traceback (most recent call last):
  ...
  File ".../repos/manticore/manticore/core/smtlib/operators.py", line 172, in CONCAT
    result = (result << arg_size) | (arg & ((1 << arg_size) - 1))
ValueError: negative shift count

Traceback (most recent call last):
  ...
  File ".../repos/manticore/manticore/core/smtlib/operators.py", line 172, in CONCAT
    result = (result << arg_size) | (arg & ((1 << arg_size) - 1))
MemoryError