---
name: "paxtest"
section: "1"
platform: "linux"
package: "paxtest"
version: "1:0.9.15-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/paxtest"
---

# paxtest(1)

program to test buffer overflow protection

## NAME

paxtest — program to test buffer overflow protection

## SYNOPSIS

**paxtest** \[*kiddie\|blackhat*\]  \[*logfile*\]

## DESCRIPTION

**paxtest** is a program that attempts to  test kernel enforcements over memory usage. Some attacks benefit  from kernels that do not impose limitations. For example, execution  in some memory segments makes buffer overflows possible. It is   used as a regression test suite for PaX, but might be useful  to test other memory protection patches for the kernel.

**paxtest** runs a set of programs that  attempt to subvert memory usage. For example:

```
Executable anonymous mapping             : Killed
Executable bss                           : Killed
Executable data                          : Killed
Executable heap                          : Killed
Executable stack                         : Killed
Executable anonymous mapping (mprotect)  : Killed
Executable bss (mprotect)                : Killed
Executable data (mprotect)               : Killed
Executable heap (mprotect)               : Killed
Executable shared library bss (mprotect) : Killed
Executable shared library data (mprotect): Killed
Executable stack (mprotect)              : Killed
Anonymous mapping randomisation test     : 16 bits (guessed)
Heap randomisation test (ET_EXEC)        : 13 bits (guessed)
Heap randomisation test (ET_DYN)         : 25 bits (guessed)
Main executable randomisation (ET_EXEC)  : No randomisation
Main executable randomisation (ET_DYN)   : 17 bits (guessed)
Stack randomisation test (SEGMEXEC)      : 23 bits (guessed)
Stack randomisation test (PAGEEXEC)      : 24 bits (guessed)
Return to function (strcpy)              : Vulnerable
Return to function (strcpy, RANDEXEC)    : Vulnerable
Return to function (memcpy)              : Vulnerable
Return to function (memcpy, RANDEXEC)    : Vulnerable
Executable shared library bss            : Killed
Executable shared library data           : Killed
Writable text segments                   : Killed
```

The \`\`*Executable ...*'' tests basically put an instruction   in a place  that is supposed to be data (i.e. malloced data, C variable, etc.)  and tries to execute it. The \`\`*(mprotect)*'' tests try to trick  the kernel in marking this piece of memory as executable first.  Return to function tests overwrite the return address on the stack,   these are hard to prevent from inside the kernel.    The last test tries to overwrite memory which is marked as executable.

A normal Linux kernel (unpatched to protect for buffer overflows)  will show all tests as Vulnerable and no stack  randomisation or 6 bits (due to stack colouring). In other words,   on a normal Linux kernel you can execute any data inside a process's   memory or overwrite any code at will.

This manual page was written for the **Debian** distribution  because the original program does not have a manual page.

## OPTIONS

This program can take two options: the tests to run, which   are indicated using either **kiddie** or **blackhat**       and (optionally) a file to which log all the test results. By default it  will log to the user's HOME directory in a paxtest.log file.

## SEE ALSO

For more information see  *PaX Documentation (link to URL http://pax.grsecurity.net/docs)* .

## AUTHOR

paxtest was written by Peter Busser.

This manual page was written by Javier Fernandez-Sanguino jfs@debian.org for  the **Debian** system (but may be used by others) based on the  information in the source code and Peter Busser's comments  sent to public mailing lists.  Permission is  granted to copy, distribute and/or modify this document under  the terms of the GNU Public License, Version 2   or any later version published by the Free  Software Foundation.