merge from master

This commit is contained in:
Andrea Fioraldi
2019-09-02 18:47:07 +02:00
10 changed files with 81 additions and 75 deletions

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@ -198,8 +198,8 @@
#define FATAL(x...) do { \
SAYF(bSTOP RESET_G1 CURSOR_SHOW cRST cLRD "\n[-] PROGRAM ABORT : " \
cBRI x); \
SAYF(cLRD "\n Location : " cRST "%s(), %s:%d\n\n", \
cRST x); \
SAYF(cLRD "\n Location : " cRST "%s(), %s:%u\n\n", \
__FUNCTION__, __FILE__, __LINE__); \
exit(1); \
} while (0)
@ -208,8 +208,8 @@
#define ABORT(x...) do { \
SAYF(bSTOP RESET_G1 CURSOR_SHOW cRST cLRD "\n[-] PROGRAM ABORT : " \
cBRI x); \
SAYF(cLRD "\n Stop location : " cRST "%s(), %s:%d\n\n", \
cRST x); \
SAYF(cLRD "\n Stop location : " cRST "%s(), %s:%u\n\n", \
__FUNCTION__, __FILE__, __LINE__); \
abort(); \
} while (0)
@ -219,8 +219,8 @@
#define PFATAL(x...) do { \
fflush(stdout); \
SAYF(bSTOP RESET_G1 CURSOR_SHOW cRST cLRD "\n[-] SYSTEM ERROR : " \
cBRI x); \
SAYF(cLRD "\n Stop location : " cRST "%s(), %s:%d\n", \
cRST x); \
SAYF(cLRD "\n Stop location : " cRST "%s(), %s:%u\n", \
__FUNCTION__, __FILE__, __LINE__); \
SAYF(cLRD " OS message : " cRST "%s\n", strerror(errno)); \
exit(1); \

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@ -1,6 +1,4 @@
===================================
libdislocator, an abusive allocator
===================================
# libdislocator, an abusive allocator
(See ../docs/README for the general instruction manual.)
@ -45,7 +43,9 @@ when fuzzing small, self-contained binaries.
To use this library, run AFL like so:
```
AFL_PRELOAD=/path/to/libdislocator.so ./afl-fuzz [...other params...]
```
You *have* to specify path, even if it's just ./libdislocator.so or
$PWD/libdislocator.so.

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@ -1,10 +1,8 @@
=========================================
strcmp() / memcmp() token capture library
=========================================
# strcmp() / memcmp() token capture library
(See ../docs/README for the general instruction manual.)
This Linux-only companion library allows you to instrument strcmp(), memcmp(),
This Linux-only companion library allows you to instrument `strcmp()`, `memcmp()`,
and related functions to automatically extract syntax tokens passed to any of
these libcalls. The resulting list of tokens may be then given as a starting
dictionary to afl-fuzz (the -x option) to improve coverage on subsequent
@ -31,15 +29,18 @@ with -fno-builtin and is linked dynamically. If you wish to automate the first
part without mucking with CFLAGS in Makefiles, you can set AFL_NO_BUILTIN=1
when using afl-gcc. This setting specifically adds the following flags:
```
-fno-builtin-strcmp -fno-builtin-strncmp -fno-builtin-strcasecmp
-fno-builtin-strcasencmp -fno-builtin-memcmp -fno-builtin-strstr
-fno-builtin-strcasestr
```
The next step is simply loading this library via LD_PRELOAD. The optimal usage
pattern is to allow afl-fuzz to fuzz normally for a while and build up a corpus,
and then fire off the target binary, with libtokencap.so loaded, on every file
found by AFL in that earlier run. This demonstrates the basic principle:
```
export AFL_TOKEN_FILE=$PWD/temp_output.txt
for i in <out_dir>/queue/id*; do
@ -48,6 +49,7 @@ found by AFL in that earlier run. This demonstrates the basic principle:
done
sort -u temp_output.txt >afl_dictionary.txt
```
If you don't get any results, the target library is probably not using strcmp()
and memcmp() to parse input; or you haven't compiled it with -fno-builtin; or
@ -55,7 +57,7 @@ the whole thing isn't dynamically linked, and LD_PRELOAD is having no effect.
PS. The library is Linux-only because there is probably no particularly portable
and non-invasive way to distinguish between read-only and read-write memory
mappings. The __tokencap_load_mappings() function is the only thing that would
mappings. The `__tokencap_load_mappings()` function is the only thing that would
need to be changed for other OSes. Porting to platforms with /proc/<pid>/maps
(e.g., FreeBSD) should be trivial.

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@ -1,6 +1,6 @@
# InsTrim
InsTrim: Lightweight Instrumentation for Coverage-guided Fuzzing
InsTrim: Lightweight Instrumentation for Coverage-guided Fuzzing
## Introduction
@ -8,17 +8,15 @@ InsTrim uses CFG and markers to instrument just what is necessary in the
binary in llvm_mode. It is about 20-25% faster but as a cost has a lower
path discovery.
## Usage
Set the environment variable AFL_LLVM_INSTRIM=1
Set the environment variable `AFL_LLVM_INSTRIM=1`.
There is also an advanced mode which instruments loops in a way so that
afl-fuzz can see which loop path has been selected but not being able to
see how often the loop has been rerun.
This again is a tradeoff for speed for less path information.
To enable this mode set AFL_LLVM_INSTRIM_LOOPHEAD=1
To enable this mode set `AFL_LLVM_INSTRIM_LOOPHEAD=1`.
## Background

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@ -1,20 +0,0 @@
Usage
=====
By default the passes will not run when you compile programs using
afl-clang-fast. Hence, you can use AFL as usual.
To enable the passes you must set environment variables before you
compile the target project.
The following options exist:
export AFL_LLVM_LAF_SPLIT_SWITCHES=1 Enables the split-switches pass.
export AFL_LLVM_LAF_TRANSFORM_COMPARES=1 Enables the transform-compares pass
(strcmp, memcmp, strncmp, strcasecmp, strncasecmp).
export AFL_LLVM_LAF_SPLIT_COMPARES=1 Enables the split-compares pass.
By default it will split all compares with a bit width <= 64 bits.
You can change this behaviour by setting
export AFL_LLVM_LAF_SPLIT_COMPARES_BITW=<bit_width>.

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@ -0,0 +1,25 @@
# laf-intel instrumentation
## Usage
By default the passes will not run when you compile programs using
afl-clang-fast. Hence, you can use AFL as usual.
To enable the passes you must set environment variables before you
compile the target project.
The following options exist:
`export AFL_LLVM_LAF_SPLIT_SWITCHES=1`
Enables the split-switches pass.
`export AFL_LLVM_LAF_TRANSFORM_COMPARES=1`
Enables the transform-compares pass (strcmp, memcmp, strncmp, strcasecmp, strncasecmp).
`export AFL_LLVM_LAF_SPLIT_COMPARES=1`
Enables the split-compares pass.
By default it will split all compares with a bit width <= 64 bits.
You can change this behaviour by setting `export AFL_LLVM_LAF_SPLIT_COMPARES_BITW=<bit_width>`.

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@ -1,12 +1,9 @@
============================================
Fast LLVM-based instrumentation for afl-fuzz
============================================
# Fast LLVM-based instrumentation for afl-fuzz
(See ../docs/README for the general instruction manual.)
(See ../gcc_plugin/README.gcc for the GCC-based instrumentation.)
1) Introduction
---------------
## 1) Introduction
! llvm_mode works with llvm versions 3.8.0 up to 9 !
@ -38,8 +35,7 @@ co-exists with the original code.
The idea and much of the implementation comes from Laszlo Szekeres.
2) How to use this
------------------
## 2) How to use this
In order to leverage this mechanism, you need to have clang installed on your
system. You should also make sure that the llvm-config tool is in your path
@ -63,8 +59,10 @@ called afl-clang-fast and afl-clang-fast++ in the parent directory. Once this
is done, you can instrument third-party code in a way similar to the standard
operating mode of AFL, e.g.:
```
CC=/path/to/afl/afl-clang-fast ./configure [...options...]
make
```
Be sure to also include CXX set to afl-clang-fast++ for C++ code.
@ -78,7 +76,7 @@ Note: if you want the LLVM helper to be installed on your system for all
users, you need to build it before issuing 'make install' in the parent
directory.
3) Options
## 3) Options
Several options are present to make llvm_mode faster or help it rearrange
the code to make afl-fuzz path discovery easier.
@ -101,15 +99,12 @@ is not optimal and was only fixed in llvm 9.
You can set this with AFL_LLVM_NOT_ZERO=1
See README.neverzero
4) Gotchas, feedback, bugs
--------------------------
## 4) Gotchas, feedback, bugs
This is an early-stage mechanism, so field reports are welcome. You can send bug
reports to <afl-users@googlegroups.com>.
5) Bonus feature #1: deferred initialization
--------------------------------------------
## 5) Bonus feature #1: deferred initialization
AFL tries to optimize performance by executing the targeted binary just once,
stopping it just before main(), and then cloning this "master" process to get
@ -145,9 +140,11 @@ a location after:
With the location selected, add this code in the appropriate spot:
```c
#ifdef __AFL_HAVE_MANUAL_CONTROL
__AFL_INIT();
#endif
```
You don't need the #ifdef guards, but including them ensures that the program
will keep working normally when compiled with a tool other than afl-clang-fast.
@ -155,8 +152,7 @@ will keep working normally when compiled with a tool other than afl-clang-fast.
Finally, recompile the program with afl-clang-fast (afl-gcc or afl-clang will
*not* generate a deferred-initialization binary) - and you should be all set!
6) Bonus feature #2: persistent mode
------------------------------------
## 6) Bonus feature #2: persistent mode
Some libraries provide APIs that are stateless, or whose state can be reset in
between processing different input files. When such a reset is performed, a
@ -165,6 +161,7 @@ eliminating the need for repeated fork() calls and the associated OS overhead.
The basic structure of the program that does this would be:
```c
while (__AFL_LOOP(1000)) {
/* Read input data. */
@ -174,6 +171,7 @@ The basic structure of the program that does this would be:
}
/* Exit normally */
```
The numerical value specified within the loop controls the maximum number
of iterations before AFL will restart the process from scratch. This minimizes
@ -182,8 +180,8 @@ and going much higher increases the likelihood of hiccups without giving you
any real performance benefits.
A more detailed template is shown in ../experimental/persistent_demo/.
Similarly to the previous mode, the feature works only with afl-clang-fast;
#ifdef guards can be used to suppress it when using other compilers.
Similarly to the previous mode, the feature works only with afl-clang-fast; #ifdef
guards can be used to suppress it when using other compilers.
Note that as with the previous mode, the feature is easy to misuse; if you
do not fully reset the critical state, you may end up with false positives or
@ -195,8 +193,7 @@ PS. Because there are task switches still involved, the mode isn't as fast as
faster than the normal fork() model, and compared to in-process fuzzing,
should be a lot more robust.
8) Bonus feature #3: new 'trace-pc-guard' mode
----------------------------------------------
## 8) Bonus feature #3: new 'trace-pc-guard' mode
Recent versions of LLVM are shipping with a built-in execution tracing feature
that provides AFL with the necessary tracing data without the need to
@ -207,7 +204,9 @@ post-process the assembly or install any compiler plugins. See:
If you have a sufficiently recent compiler and want to give it a try, build
afl-clang-fast this way:
```
AFL_TRACE_PC=1 make clean all
```
Note that this mode is currently about 20% slower than "vanilla" afl-clang-fast,
and about 5-10% slower than afl-clang. This is likely because the

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@ -1,5 +1,6 @@
Usage
=====
# NeverZero counters for LLVM instrumentation
## Usage
In larger, complex or reiterative programs the map that collects the edge pairs
can easily fill up and wrap.
@ -18,5 +19,6 @@ in version 9 and onwards.
If you want to enable this for llvm < 9 then set
```
export AFL_LLVM_NOT_ZERO=1
```

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@ -1,6 +1,4 @@
========================================
Using afl++ with partial instrumentation
========================================
# Using afl++ with partial instrumentation
This file describes how you can selectively instrument only the source files
that are interesting to you using the LLVM instrumentation provided by
@ -8,9 +6,7 @@ Using afl++ with partial instrumentation
Originally developed by Christian Holler (:decoder) <choller@mozilla.com>.
1) Description and purpose
--------------------------
## 1) Description and purpose
When building and testing complex programs where only a part of the program is
the fuzzing target, it often helps to only instrument the necessary parts of
@ -23,15 +19,13 @@ mode of AFLFuzz that allows you to specify on a source file level which files
should be compiled with or without instrumentation.
2) Building the LLVM module
---------------------------
## 2) Building the LLVM module
The new code is part of the existing afl++ LLVM module in the llvm_mode/
subdirectory. There is nothing specifically to do :)
3) How to use the partial instrumentation mode
----------------------------------------------
## 3) How to use the partial instrumentation mode
In order to build with partial instrumentation, you need to build with
afl-clang-fast and afl-clang-fast++ respectively. The only required change is
@ -45,21 +39,27 @@ matching when absolute paths are used during compilation).
For example if your source tree looks like this:
```
project/
project/feature_a/a1.cpp
project/feature_a/a2.cpp
project/feature_b/b1.cpp
project/feature_b/b2.cpp
```
And you only want to test feature_a, then create a whitelist file containing:
```
feature_a/a1.cpp
feature_a/a2.cpp
```
However if the whitelist file contains this, it works as well:
```
a1.cpp
a2.cpp
```
but it might lead to files being unwantedly instrumented if the same filename
exists somewhere else in the project.

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@ -1,10 +1,8 @@
================================================================
strcmp() / memcmp() CompareCoverage library for AFLplusplus-QEMU
================================================================
# strcmp() / memcmp() CompareCoverage library for afl++ QEMU
Written by Andrea Fioraldi <andreafioraldi@gmail.com>
This Linux-only companion library allows you to instrument strcmp(), memcmp(),
This Linux-only companion library allows you to instrument `strcmp()`, `memcmp()`,
and related functions to log the CompareCoverage of these libcalls.
Use this with caution. While this can speedup a lot the bypass of hard
@ -22,10 +20,12 @@ library and QEMU but build it with afl-clang-fast and the laf-intel options.
To use this library make sure to preload it with AFL_PRELOAD.
```
export AFL_PRELOAD=/path/to/libcompcov.so
export AFL_COMPCOV_LEVEL=1
afl-fuzz -Q -i input -o output <your options> -- <target args>
```
The AFL_COMPCOV_LEVEL tells to QEMU and libcompcov how to log comaprisons.
Level 1 logs just comparison with immediates / read-only memory and level 2