NAME
fuzz - stress test programs
SYNOPSIS
fuzz [-t|--timeout timeinsecs] [-p|--printable] [-n|--newlines N]
[-l|--length totlen] [-m|--maxline maxlinelen] [-r|--runcount numruns]
[-b|--bytes] [-c|--chroot] [-u|--user username] [-a|--args]
[-o|--omitdata] [-e|--execute filename] [-x|--maxargs numargs]
[-d|--dontask] [-y|--mararglen arglen] [-V|--version] [-i|--priority]
target targetarg...
DESCRIPTION
fuzz is a program designed to find bugs in other programs. It does this
by doing a form of black box testing. It does this by running the
target program multiple times and passing it random input. Right now
this can come from one of two places, stdin and the command line
arguments. Testing completes whenever the program either the requested
number of runs finishes successufully or the program crashes.
Any arguments following the target program are passed directly to the
target program.
NOTE: If the program is not in PATH, it must be referred to using
absolute path.
OPTIONS
-a, --args
In addition to passing random data via stdin, pass random
command line arguments. This simply sets the number or random
arguments to be passed to 256. See the BUGS section.
-b, --bytes
In addition to counting through the number of runs. Count
through the bytes being sent through stdin to the program. This
option really serves no purpose other than making something
interesting to watch.
-c, --chroot
Since there is no telling what a program will do when given
random input. this allows a program to be sort of caged while it
is run so that the damage that it may be able to do is
minimized. This requires that the fuzz be run as root. It will
drop privlages before it runs the test program. This option is
best used in conjunction with the --user option. This often
times requires that a program is statically linked.
-d, --dontask
In the cases where the target program is for sure part of a
package and the packaging information will provide the needed
version information then you can use this option to avoid being
asked what the version is.
-i, --priority
Run at a specified priority.
-l, --length LENGTH
The length in bytes of the data stream to pass through stdin
into the target program. The default length is 100K.
-m, --maxline MAXLINELEN
Specify the maximum line length within the random data stream
passed into stdin.
-n, --newlines N
Include random N newlines in the input stream.
-o, --omitdata
Some programs don’t take input from stdin. They only take input
from the command line arguments. If this is the case simply use
the --omitdata option.
-p, --printable
This limits both the stdin and the command line arguments to
only printable characters. By default fuzz passes fully random
bytes into the target program.
-r, --runcount RUNCOUNT
The number of times to run the target program. The default is
10,000.
-t, --timeout TIME
This sets the number of seconds that the fuzz will wait for the
other program before it assumes that the program is hung. The
default value is 120 seconds. This is sensing of when a program
is hung is not entirely reliable. See the BUGS section.
-u, --user USERNAME
Since there is no telling what a program will do when given
random input, this specifies what user the target program will
be run as so that it is easy to find and repair anything that
may have been scribbled across your file system. This option was
designed to be used in conjuntion with the --chroot option and
will only work if fuzz is run as root.
-V, --version
Print the version of fuzz and exit.
-x. --maxargs NUMARGS
This is to set the maximum number of arguments that are passed
to each invocation of the target program.
-y, --maxarglen ARGLEN
Sets the maximum length of an arguments passed to the target
program.
EXAMPLES
Check grep:
fuzz grep foo
Run program with different user:
fuzz --chroot --user nobody cpio -i
When program is not in path, use absolute patch to access it:
fuzz ./src/myprogram
BUGS
The random arg functions doesn’t work very well right now. The
arguments passed are so random that the program usually just prints out
the usage message and then terminates. This will become much more
useful later when we are mating data sets with the intention of
maximizing code coverage.
AUTHORS
Ben Woodard <ben@valinux.com>