From d6beac5235118b251deb18a6579aab85271eaa7b Mon Sep 17 00:00:00 2001 From: Andrea Fioraldi Date: Mon, 29 Jul 2019 16:09:28 +0200 Subject: compcov levels to enable the instrumentation of only immediates --- qemu_mode/patches/afl-qemu-cpu-translate-inl.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'qemu_mode/patches/afl-qemu-cpu-translate-inl.h') diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h index 0ca89c98..4716c2ac 100644 --- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h @@ -40,7 +40,7 @@ extern unsigned char *afl_area_ptr; extern unsigned int afl_inst_rms; extern abi_ulong afl_start_code, afl_end_code; -extern u8 afl_enable_compcov; +extern u8 afl_compcov_level; void tcg_gen_afl_compcov_log_call(void *func, target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2); @@ -95,11 +95,14 @@ static void afl_compcov_log_64(target_ulong cur_loc, target_ulong arg1, static void afl_gen_compcov(target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2, - TCGMemOp ot) { + TCGMemOp ot, int is_imm) { void *func; - if (!afl_enable_compcov || cur_loc > afl_end_code || cur_loc < afl_start_code) + if (!afl_compcov_level || cur_loc > afl_end_code || cur_loc < afl_start_code) + return; + + if (!is_imm && afl_compcov_level < 2) return; switch (ot) { -- cgit 1.4.1 From 733c8e4c349562fd02d0238be486ecbdf0640fd0 Mon Sep 17 00:00:00 2001 From: Andrea Fioraldi Date: Wed, 28 Aug 2019 18:42:21 +0200 Subject: better neverzero with adc + neverzero for compcov --- qemu_mode/patches/afl-qemu-cpu-translate-inl.h | 36 +++++++++++++++------- qemu_mode/patches/afl-qemu-translate-inl.h | 3 +- unicorn_mode/patches/afl-unicorn-cpu-inl.h | 3 +- unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h | 36 +++++++++++++++------- 4 files changed, 52 insertions(+), 26 deletions(-) (limited to 'qemu_mode/patches/afl-qemu-cpu-translate-inl.h') diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h index 4716c2ac..f85a86d7 100644 --- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h @@ -45,11 +45,25 @@ extern u8 afl_compcov_level; void tcg_gen_afl_compcov_log_call(void *func, target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2); +#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) +# define INC_AFL_AREA(loc) \ + asm volatile ( \ + "incb (%0, %1, 1)\n" \ + "adc $0, (%0, %1, 1)\n" \ + : /* no out */ \ + : "r" (afl_area_ptr), "r" (loc) \ + : "memory", "eax" \ + ) +#else +# define INC_AFL_AREA(loc) \ + afl_area_ptr[loc]++ +#endif + static void afl_compcov_log_16(target_ulong cur_loc, target_ulong arg1, target_ulong arg2) { if ((arg1 & 0xff) == (arg2 & 0xff)) { - afl_area_ptr[cur_loc]++; + INC_AFL_AREA(cur_loc); } } @@ -57,11 +71,11 @@ static void afl_compcov_log_32(target_ulong cur_loc, target_ulong arg1, target_ulong arg2) { if ((arg1 & 0xff) == (arg2 & 0xff)) { - afl_area_ptr[cur_loc]++; + INC_AFL_AREA(cur_loc); if ((arg1 & 0xffff) == (arg2 & 0xffff)) { - afl_area_ptr[cur_loc +1]++; + INC_AFL_AREA(cur_loc +1); if ((arg1 & 0xffffff) == (arg2 & 0xffffff)) { - afl_area_ptr[cur_loc +2]++; + INC_AFL_AREA(cur_loc +2); } } } @@ -71,19 +85,19 @@ static void afl_compcov_log_64(target_ulong cur_loc, target_ulong arg1, target_ulong arg2) { if ((arg1 & 0xff) == (arg2 & 0xff)) { - afl_area_ptr[cur_loc]++; + INC_AFL_AREA(cur_loc); if ((arg1 & 0xffff) == (arg2 & 0xffff)) { - afl_area_ptr[cur_loc +1]++; + INC_AFL_AREA(cur_loc +1); if ((arg1 & 0xffffff) == (arg2 & 0xffffff)) { - afl_area_ptr[cur_loc +2]++; + INC_AFL_AREA(cur_loc +2); if ((arg1 & 0xffffffff) == (arg2 & 0xffffffff)) { - afl_area_ptr[cur_loc +3]++; + INC_AFL_AREA(cur_loc +3); if ((arg1 & 0xffffffffff) == (arg2 & 0xffffffffff)) { - afl_area_ptr[cur_loc +4]++; + INC_AFL_AREA(cur_loc +4); if ((arg1 & 0xffffffffffff) == (arg2 & 0xffffffffffff)) { - afl_area_ptr[cur_loc +5]++; + INC_AFL_AREA(cur_loc +5); if ((arg1 & 0xffffffffffffff) == (arg2 & 0xffffffffffffff)) { - afl_area_ptr[cur_loc +6]++; + INC_AFL_AREA(cur_loc +6); } } } diff --git a/qemu_mode/patches/afl-qemu-translate-inl.h b/qemu_mode/patches/afl-qemu-translate-inl.h index f82d1217..48d05179 100644 --- a/qemu_mode/patches/afl-qemu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-translate-inl.h @@ -51,8 +51,7 @@ void afl_maybe_log(target_ulong cur_loc) { #if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) asm volatile ( "incb (%0, %1, 1)\n" - "seto %%al\n" - "addb %%al, (%0, %1, 1)\n" + "adc $0, (%0, %1, 1)\n" : /* no out */ : "r" (afl_area_ptr), "r" (afl_idx) : "memory", "eax" diff --git a/unicorn_mode/patches/afl-unicorn-cpu-inl.h b/unicorn_mode/patches/afl-unicorn-cpu-inl.h index 28400357..187a0ce6 100644 --- a/unicorn_mode/patches/afl-unicorn-cpu-inl.h +++ b/unicorn_mode/patches/afl-unicorn-cpu-inl.h @@ -252,8 +252,7 @@ static inline void afl_maybe_log(struct uc_struct* uc, unsigned long cur_loc) { #if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) asm volatile ( "incb (%0, %1, 1)\n" - "seto %%al\n" - "addb %%al, (%0, %1, 1)\n" + "adc $0, (%0, %1, 1)\n" : /* no out */ : "r" (uc->afl_area_ptr), "r" (afl_idx) : "memory", "eax" diff --git a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h index 9e56484b..e59d7b15 100644 --- a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h +++ b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h @@ -32,13 +32,27 @@ #include "uc_priv.h" +#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) +# define INC_AFL_AREA(loc) \ + asm volatile ( \ + "incb (%0, %1, 1)\n" \ + "adc $0, (%0, %1, 1)\n" \ + : /* no out */ \ + : "r" (uc->afl_area_ptr), "r" (loc) \ + : "memory", "eax" \ + ) +#else +# define INC_AFL_AREA(loc) \ + uc->afl_area_ptr[loc]++ +#endif + void HELPER(afl_compcov_log_16)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, uint64_t arg2) { struct uc_struct* uc = uc_ptr; if ((arg1 & 0xff) == (arg2 & 0xff)) { - uc->afl_area_ptr[cur_loc]++; + INC_AFL_AREA(cur_loc); } } @@ -48,11 +62,11 @@ void HELPER(afl_compcov_log_32)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, struct uc_struct* uc = uc_ptr; if ((arg1 & 0xff) == (arg2 & 0xff)) { - uc->afl_area_ptr[cur_loc]++; + INC_AFL_AREA(cur_loc); if ((arg1 & 0xffff) == (arg2 & 0xffff)) { - uc->afl_area_ptr[cur_loc +1]++; + INC_AFL_AREA(cur_loc +1); if ((arg1 & 0xffffff) == (arg2 & 0xffffff)) { - uc->afl_area_ptr[cur_loc +2]++; + INC_AFL_AREA(cur_loc +2); } } } @@ -64,19 +78,19 @@ void HELPER(afl_compcov_log_64)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, struct uc_struct* uc = uc_ptr; if ((arg1 & 0xff) == (arg2 & 0xff)) { - uc->afl_area_ptr[cur_loc]++; + INC_AFL_AREA(cur_loc); if ((arg1 & 0xffff) == (arg2 & 0xffff)) { - uc->afl_area_ptr[cur_loc +1]++; + INC_AFL_AREA(cur_loc +1); if ((arg1 & 0xffffff) == (arg2 & 0xffffff)) { - uc->afl_area_ptr[cur_loc +2]++; + INC_AFL_AREA(cur_loc +2); if ((arg1 & 0xffffffff) == (arg2 & 0xffffffff)) { - uc->afl_area_ptr[cur_loc +3]++; + INC_AFL_AREA(cur_loc +3); if ((arg1 & 0xffffffffff) == (arg2 & 0xffffffffff)) { - uc->afl_area_ptr[cur_loc +4]++; + INC_AFL_AREA(cur_loc +4); if ((arg1 & 0xffffffffffff) == (arg2 & 0xffffffffffff)) { - uc->afl_area_ptr[cur_loc +5]++; + INC_AFL_AREA(cur_loc +5); if ((arg1 & 0xffffffffffffff) == (arg2 & 0xffffffffffffff)) { - uc->afl_area_ptr[cur_loc +6]++; + INC_AFL_AREA(cur_loc +6); } } } -- cgit 1.4.1 From 892513708bb5f68b15610fe0c74b892d4421c8cd Mon Sep 17 00:00:00 2001 From: Andrea Fioraldi Date: Wed, 28 Aug 2019 19:07:19 +0200 Subject: solved MAP_SIZE overflow --- qemu_mode/patches/afl-qemu-cpu-translate-inl.h | 2 +- unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'qemu_mode/patches/afl-qemu-cpu-translate-inl.h') diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h index f85a86d7..c0caeefc 100644 --- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h @@ -134,7 +134,7 @@ static void afl_gen_compcov(target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2, } cur_loc = (cur_loc >> 4) ^ (cur_loc << 8); - cur_loc &= MAP_SIZE - 1; + cur_loc &= MAP_SIZE - 7; if (cur_loc >= afl_inst_rms) return; diff --git a/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h b/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h index 9c7a14dc..7e8f47c9 100644 --- a/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h +++ b/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h @@ -42,7 +42,7 @@ static void afl_gen_compcov(TCGContext *s, uint64_t cur_loc, TCGv_i64 arg1, return; cur_loc = (cur_loc >> 4) ^ (cur_loc << 8); - cur_loc &= MAP_SIZE - 1; + cur_loc &= MAP_SIZE - 7; if (cur_loc >= s->uc->afl_inst_rms) return; -- cgit 1.4.1 From 3f2a317af09982a47340593b224a10b79a81d303 Mon Sep 17 00:00:00 2001 From: Dominik Maier Date: Thu, 29 Aug 2019 03:06:24 +0200 Subject: Fixed SIGSEV due to wrong pointer size --- qemu_mode/patches/afl-qemu-cpu-translate-inl.h | 2 +- qemu_mode/patches/afl-qemu-translate-inl.h | 2 +- unicorn_mode/patches/afl-unicorn-cpu-inl.h | 2 +- unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) (limited to 'qemu_mode/patches/afl-qemu-cpu-translate-inl.h') diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h index c0caeefc..e91e9ffa 100644 --- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h @@ -49,7 +49,7 @@ void tcg_gen_afl_compcov_log_call(void *func, target_ulong cur_loc, # define INC_AFL_AREA(loc) \ asm volatile ( \ "incb (%0, %1, 1)\n" \ - "adc $0, (%0, %1, 1)\n" \ + "adcb $0, (%0, %1, 1)\n" \ : /* no out */ \ : "r" (afl_area_ptr), "r" (loc) \ : "memory", "eax" \ diff --git a/qemu_mode/patches/afl-qemu-translate-inl.h b/qemu_mode/patches/afl-qemu-translate-inl.h index 48d05179..a33e17b7 100644 --- a/qemu_mode/patches/afl-qemu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-translate-inl.h @@ -51,7 +51,7 @@ void afl_maybe_log(target_ulong cur_loc) { #if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) asm volatile ( "incb (%0, %1, 1)\n" - "adc $0, (%0, %1, 1)\n" + "adcb $0, (%0, %1, 1)\n" : /* no out */ : "r" (afl_area_ptr), "r" (afl_idx) : "memory", "eax" diff --git a/unicorn_mode/patches/afl-unicorn-cpu-inl.h b/unicorn_mode/patches/afl-unicorn-cpu-inl.h index 187a0ce6..ff194696 100644 --- a/unicorn_mode/patches/afl-unicorn-cpu-inl.h +++ b/unicorn_mode/patches/afl-unicorn-cpu-inl.h @@ -252,7 +252,7 @@ static inline void afl_maybe_log(struct uc_struct* uc, unsigned long cur_loc) { #if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) asm volatile ( "incb (%0, %1, 1)\n" - "adc $0, (%0, %1, 1)\n" + "adcb $0, (%0, %1, 1)\n" : /* no out */ : "r" (uc->afl_area_ptr), "r" (afl_idx) : "memory", "eax" diff --git a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h index e59d7b15..52cc1afb 100644 --- a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h +++ b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h @@ -36,7 +36,7 @@ # define INC_AFL_AREA(loc) \ asm volatile ( \ "incb (%0, %1, 1)\n" \ - "adc $0, (%0, %1, 1)\n" \ + "adcb $0, (%0, %1, 1)\n" \ : /* no out */ \ : "r" (uc->afl_area_ptr), "r" (loc) \ : "memory", "eax" \ -- cgit 1.4.1 From 132ad08885f95abfdcbafdf1fa33b3f12ac59538 Mon Sep 17 00:00:00 2001 From: Andrea Fioraldi Date: Thu, 29 Aug 2019 15:28:42 +0200 Subject: common header for qemu and unicorn --- qemu_mode/patches/afl-qemu-common.h | 52 ++++++++++++++++++++++ qemu_mode/patches/afl-qemu-cpu-translate-inl.h | 16 +------ qemu_mode/patches/afl-qemu-translate-inl.h | 14 +----- unicorn_mode/patches/afl-unicorn-common.h | 50 +++++++++++++++++++++ unicorn_mode/patches/afl-unicorn-cpu-inl.h | 30 ++----------- unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h | 21 ++------- 6 files changed, 113 insertions(+), 70 deletions(-) create mode 100644 qemu_mode/patches/afl-qemu-common.h create mode 100644 unicorn_mode/patches/afl-unicorn-common.h (limited to 'qemu_mode/patches/afl-qemu-cpu-translate-inl.h') diff --git a/qemu_mode/patches/afl-qemu-common.h b/qemu_mode/patches/afl-qemu-common.h new file mode 100644 index 00000000..8013800d --- /dev/null +++ b/qemu_mode/patches/afl-qemu-common.h @@ -0,0 +1,52 @@ +/* + american fuzzy lop - high-performance binary-only instrumentation + ----------------------------------------------------------------- + + Written by Andrew Griffiths and + Michal Zalewski + + Idea & design very much by Andrew Griffiths. + + TCG instrumentation and block chaining support by Andrea Biondo + + + QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi + + + Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + This code is a shim patched into the separately-distributed source + code of QEMU 3.1.0. It leverages the built-in QEMU tracing functionality + to implement AFL-style instrumentation and to take care of the remaining + parts of the AFL fork server logic. + + The resulting QEMU binary is essentially a standalone instrumentation + tool; for an example of how to leverage it for other purposes, you can + have a look at afl-showmap.c. + + */ + +#include "../../config.h" + +/* NeverZero */ + +#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) +# define INC_AFL_AREA(loc) \ + asm volatile ( \ + "incb (%0, %1, 1)\n" \ + "adcb $0, (%0, %1, 1)\n" \ + : /* no out */ \ + : "r" (afl_area_ptr), "r" (loc) \ + : "memory", "eax" \ + ) +#else +# define INC_AFL_AREA(loc) \ + afl_area_ptr[loc]++ +#endif + diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h index e91e9ffa..fc78e652 100644 --- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h @@ -32,7 +32,7 @@ */ -#include "../../config.h" +#include "afl-qemu-common.h" #include "tcg.h" #include "tcg-op.h" @@ -45,20 +45,6 @@ extern u8 afl_compcov_level; void tcg_gen_afl_compcov_log_call(void *func, target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2); -#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) -# define INC_AFL_AREA(loc) \ - asm volatile ( \ - "incb (%0, %1, 1)\n" \ - "adcb $0, (%0, %1, 1)\n" \ - : /* no out */ \ - : "r" (afl_area_ptr), "r" (loc) \ - : "memory", "eax" \ - ) -#else -# define INC_AFL_AREA(loc) \ - afl_area_ptr[loc]++ -#endif - static void afl_compcov_log_16(target_ulong cur_loc, target_ulong arg1, target_ulong arg2) { diff --git a/qemu_mode/patches/afl-qemu-translate-inl.h b/qemu_mode/patches/afl-qemu-translate-inl.h index a33e17b7..d63c5167 100644 --- a/qemu_mode/patches/afl-qemu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-translate-inl.h @@ -32,7 +32,7 @@ */ -#include "../../config.h" +#include "afl-qemu-common.h" #include "tcg-op.h" /* Declared in afl-qemu-cpu-inl.h */ @@ -48,17 +48,7 @@ void afl_maybe_log(target_ulong cur_loc) { register uintptr_t afl_idx = cur_loc ^ prev_loc; -#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) - asm volatile ( - "incb (%0, %1, 1)\n" - "adcb $0, (%0, %1, 1)\n" - : /* no out */ - : "r" (afl_area_ptr), "r" (afl_idx) - : "memory", "eax" - ); -#else - afl_area_ptr[afl_idx]++; -#endif + INC_AFL_AREA(afl_idx); prev_loc = cur_loc >> 1; diff --git a/unicorn_mode/patches/afl-unicorn-common.h b/unicorn_mode/patches/afl-unicorn-common.h new file mode 100644 index 00000000..9a1b2a6c --- /dev/null +++ b/unicorn_mode/patches/afl-unicorn-common.h @@ -0,0 +1,50 @@ +/* + american fuzzy lop - high-performance binary-only instrumentation + ----------------------------------------------------------------- + + Written by Andrew Griffiths and + Michal Zalewski + + TCG instrumentation and block chaining support by Andrea Biondo + + Adapted for afl-unicorn by Dominik Maier + + Idea & design very much by Andrew Griffiths. + + Copyright 2015, 2016 Google Inc. All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at: + + http://www.apache.org/licenses/LICENSE-2.0 + + This code is a shim patched into the separately-distributed source + code of Unicorn 1.0.1. It leverages the built-in QEMU tracing functionality + to implement AFL-style instrumentation and to take care of the remaining + parts of the AFL fork server logic. + + The resulting QEMU binary is essentially a standalone instrumentation + tool; for an example of how to leverage it for other purposes, you can + have a look at afl-showmap.c. + + */ + +#include "../../config.h" + +/* NeverZero */ + +#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) +# define INC_AFL_AREA(loc) \ + asm volatile ( \ + "incb (%0, %1, 1)\n" \ + "adcb $0, (%0, %1, 1)\n" \ + : /* no out */ \ + : "r" (afl_area_ptr), "r" (loc) \ + : "memory", "eax" \ + ) +#else +# define INC_AFL_AREA(loc) \ + afl_area_ptr[loc]++ +#endif + diff --git a/unicorn_mode/patches/afl-unicorn-cpu-inl.h b/unicorn_mode/patches/afl-unicorn-cpu-inl.h index ff194696..90937a17 100644 --- a/unicorn_mode/patches/afl-unicorn-cpu-inl.h +++ b/unicorn_mode/patches/afl-unicorn-cpu-inl.h @@ -33,7 +33,7 @@ #include #include #include -#include "../../config.h" +#include "afl-unicorn-common.h" /*************************** * VARIOUS AUXILIARY STUFF * @@ -218,17 +218,11 @@ static inline void afl_maybe_log(struct uc_struct* uc, unsigned long cur_loc) { static __thread unsigned long prev_loc; - // DEBUG - //printf("IN AFL_MAYBE_LOG 0x%lx\n", cur_loc); + u8* afl_area_ptr = uc->afl_area_ptr; - // MODIFIED FOR UNICORN MODE -> We want to log all addresses, - // so the checks for 'start < addr < end' are removed - if(!uc->afl_area_ptr) + if(!afl_area_ptr) return; - // DEBUG - //printf("afl_area_ptr = %p\n", afl_area_ptr); - /* Looks like QEMU always maps to fixed locations, so ASAN is not a concern. Phew. But instruction addresses may be aligned. Let's mangle the value to get something quasi-uniform. */ @@ -239,27 +233,11 @@ static inline void afl_maybe_log(struct uc_struct* uc, unsigned long cur_loc) { /* Implement probabilistic instrumentation by looking at scrambled block address. This keeps the instrumented locations stable across runs. */ - // DEBUG - //printf("afl_inst_rms = 0x%lx\n", afl_inst_rms); - if (cur_loc >= uc->afl_inst_rms) return; - // DEBUG - //printf("cur_loc = 0x%lx\n", cur_loc); - register uintptr_t afl_idx = cur_loc ^ prev_loc; -#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) - asm volatile ( - "incb (%0, %1, 1)\n" - "adcb $0, (%0, %1, 1)\n" - : /* no out */ - : "r" (uc->afl_area_ptr), "r" (afl_idx) - : "memory", "eax" - ); -#else - uc->afl_area_ptr[afl_idx]++; -#endif + INC_AFL_AREA(afl_idx); prev_loc = cur_loc >> 1; diff --git a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h index 52cc1afb..0019bbfa 100644 --- a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h +++ b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h @@ -31,25 +31,12 @@ */ #include "uc_priv.h" - -#if (defined(__x86_64__) || defined(__i386__)) && defined(AFL_QEMU_NOT_ZERO) -# define INC_AFL_AREA(loc) \ - asm volatile ( \ - "incb (%0, %1, 1)\n" \ - "adcb $0, (%0, %1, 1)\n" \ - : /* no out */ \ - : "r" (uc->afl_area_ptr), "r" (loc) \ - : "memory", "eax" \ - ) -#else -# define INC_AFL_AREA(loc) \ - uc->afl_area_ptr[loc]++ -#endif +#include "afl-unicorn-common.h" void HELPER(afl_compcov_log_16)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, uint64_t arg2) { - struct uc_struct* uc = uc_ptr; + u8* afl_area_ptr = ((struct uc_struct*)uc_ptr)->afl_area_ptr; if ((arg1 & 0xff) == (arg2 & 0xff)) { INC_AFL_AREA(cur_loc); @@ -59,7 +46,7 @@ void HELPER(afl_compcov_log_16)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, void HELPER(afl_compcov_log_32)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, uint64_t arg2) { - struct uc_struct* uc = uc_ptr; + u8* afl_area_ptr = ((struct uc_struct*)uc_ptr)->afl_area_ptr; if ((arg1 & 0xff) == (arg2 & 0xff)) { INC_AFL_AREA(cur_loc); @@ -75,7 +62,7 @@ void HELPER(afl_compcov_log_32)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, void HELPER(afl_compcov_log_64)(void* uc_ptr, uint64_t cur_loc, uint64_t arg1, uint64_t arg2) { - struct uc_struct* uc = uc_ptr; + u8* afl_area_ptr = ((struct uc_struct*)uc_ptr)->afl_area_ptr; if ((arg1 & 0xff) == (arg2 & 0xff)) { INC_AFL_AREA(cur_loc); -- cgit 1.4.1 From 7b36afd5f16894257c92695d200e59eb51d08e1c Mon Sep 17 00:00:00 2001 From: Andrea Fioraldi Date: Fri, 30 Aug 2019 11:38:33 +0200 Subject: modernize docs and readme for qemu and unicorn --- docs/unicorn_mode.txt | 109 --------------- qemu_mode/README.md | 137 +++++++++++++++++++ qemu_mode/README.qemu | 146 --------------------- qemu_mode/build_qemu_support.sh | 11 +- qemu_mode/libcompcov/libcompcov.so.c | 2 +- qemu_mode/patches/afl-qemu-common.h | 15 +-- qemu_mode/patches/afl-qemu-cpu-inl.h | 15 +-- qemu_mode/patches/afl-qemu-cpu-translate-inl.h | 17 ++- qemu_mode/patches/afl-qemu-tcg-inl.h | 15 +-- qemu_mode/patches/afl-qemu-translate-inl.h | 15 +-- unicorn_mode/README.md | 130 +++++++++++++++--- unicorn_mode/build_unicorn_support.sh | 12 +- unicorn_mode/patches/afl-unicorn-common.h | 18 +-- unicorn_mode/patches/afl-unicorn-cpu-inl.h | 18 +-- .../patches/afl-unicorn-cpu-translate-inl.h | 18 +-- unicorn_mode/patches/afl-unicorn-tcg-op-inl.h | 18 +-- unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h | 18 +-- unicorn_mode/samples/compcov_x64/COMPILE.md | 3 +- unicorn_mode/samples/compcov_x64/compcov_target.c | 2 +- unicorn_mode/samples/simple/COMPILE.md | 5 +- 20 files changed, 353 insertions(+), 371 deletions(-) delete mode 100644 docs/unicorn_mode.txt create mode 100644 qemu_mode/README.md delete mode 100644 qemu_mode/README.qemu (limited to 'qemu_mode/patches/afl-qemu-cpu-translate-inl.h') diff --git a/docs/unicorn_mode.txt b/docs/unicorn_mode.txt deleted file mode 100644 index b691fff8..00000000 --- a/docs/unicorn_mode.txt +++ /dev/null @@ -1,109 +0,0 @@ -========================================================= -Unicorn-based binary-only instrumentation for afl-fuzz -========================================================= - -1) Introduction ---------------- - -The code in ./unicorn_mode allows you to build a standalone feature that -leverages the Unicorn Engine and allows callers to obtain instrumentation -output for black-box, closed-source binary code snippets. This mechanism -can be then used by afl-fuzz to stress-test targets that couldn't be built -with afl-gcc or used in QEMU mode, or with other extensions such as -TriforceAFL. - -There is a significant performance penalty compared to native AFL, -but at least we're able to use AFL on these binaries, right? - -The idea and much of the implementation comes from Nathan Voss . - -2) How to use -------------- - -Requirements: you need an installed python2 environment. - -*** Building AFL's Unicorn Mode *** - -First, make afl as usual. -Once that completes successfully you need to build and add in the Unicorn Mode -features: - - $ cd unicorn_mode - $ ./build_unicorn_support.sh - -NOTE: This script downloads a recent Unicorn Engine commit that has been tested -and is stable-ish from the Unicorn github page. If you are offline, you'll need -to hack up this script a little bit and supply your own copy of Unicorn's latest -stable release. It's not very hard, just check out the beginning of the -build_unicorn_support.sh script and adjust as necessary. - -Building Unicorn will take a little bit (~5-10 minutes). Once it completes -it automatically compiles a sample application and verify that it works. - -*** Fuzzing with Unicorn Mode *** - -To really use unicorn-mode effectively you need to prepare the following: - - * Relevant binary code to be fuzzed - * Knowledge of the memory map and good starting state - * Folder containing sample inputs to start fuzzing with - - Same ideas as any other AFL inputs - - Quality/speed of results will depend greatly on quality of starting - samples - - See AFL's guidance on how to create a sample corpus - * Unicorn-based test harness which: - - Adds memory map regions - - Loads binary code into memory - - Emulates at least one instruction* - - Yeah, this is lame. See 'Gotchas' section below for more info - - Loads and verifies data to fuzz from a command-line specified file - - AFL will provide mutated inputs by changing the file passed to - the test harness - - Presumably the data to be fuzzed is at a fixed buffer address - - If input constraints (size, invalid bytes, etc.) are known they - should be checked after the file is loaded. If a constraint - fails, just exit the test harness. AFL will treat the input as - 'uninteresting' and move on. - - Sets up registers and memory state for beginning of test - - Emulates the interested code from beginning to end - - If a crash is detected, the test harness must 'crash' by - throwing a signal (SIGSEGV, SIGKILL, SIGABORT, etc.) - -Once you have all those things ready to go you just need to run afl-fuzz in -'unicorn-mode' by passing in the '-U' flag: - - $ afl-fuzz -U -m none -i /path/to/inputs -o /path/to/results -- ./test_harness @@ - -The normal afl-fuzz command line format applies to everything here. Refer to -AFL's main documentation for more info about how to use afl-fuzz effectively. - -For a much clearer vision of what all of this looks like, please refer to the -sample provided in the 'unicorn_mode/samples' directory. There is also a blog -post that goes over the basics at: - -https://medium.com/@njvoss299/afl-unicorn-fuzzing-arbitrary-binary-code-563ca28936bf - -The 'helper_scripts' directory also contains several helper scripts that allow you -to dump context from a running process, load it, and hook heap allocations. For details -on how to use this check out the follow-up blog post to the one linked above. - -A example use of AFL-Unicorn mode is discussed in the Paper Unicorefuzz: -https://www.usenix.org/conference/woot19/presentation/maier - -3) Gotchas, feedback, bugs --------------------------- - -To make sure that AFL's fork server starts up correctly the Unicorn test -harness script must emulate at least one instruction before loading the -data that will be fuzzed from the input file. It doesn't matter what the -instruction is, nor if it is valid. This is an artifact of how the fork-server -is started and could likely be fixed with some clever re-arranging of the -patches applied to Unicorn. - -Running the build script builds Unicorn and its python bindings and installs -them on your system. This installation will supersede any existing Unicorn -installation with the patched afl-unicorn version. - -Refer to the unicorn_mode/samples/arm_example/arm_tester.c for an example -of how to do this properly! If you don't get this right, AFL will not -load any mutated inputs and your fuzzing will be useless! diff --git a/qemu_mode/README.md b/qemu_mode/README.md new file mode 100644 index 00000000..610f6860 --- /dev/null +++ b/qemu_mode/README.md @@ -0,0 +1,137 @@ +# High-performance binary-only instrumentation for afl-fuzz + + (See ../docs/README for the general instruction manual.) + +## 1) Introduction + +The code in this directory allows you to build a standalone feature that +leverages the QEMU "user emulation" mode and allows callers to obtain +instrumentation output for black-box, closed-source binaries. This mechanism +can be then used by afl-fuzz to stress-test targets that couldn't be built +with afl-gcc. + +The usual performance cost is 2-5x, which is considerably better than +seen so far in experiments with tools such as DynamoRIO and PIN. + +The idea and much of the initial implementation comes from Andrew Griffiths. +The actual implementation on QEMU 3 (shipped with afl++) is from +Andrea Fioraldi. Special thanks to abiondo that re-enabled TCG chaining. + +## 2) How to use + +The feature is implemented with a patch to QEMU 3.1.0. The simplest way +to build it is to run ./build_qemu_support.sh. The script will download, +configure, and compile the QEMU binary for you. + +QEMU is a big project, so this will take a while, and you may have to +resolve a couple of dependencies (most notably, you will definitely need +libtool and glib2-devel). + +Once the binaries are compiled, you can leverage the QEMU tool by calling +afl-fuzz and all the related utilities with -Q in the command line. + +Note that QEMU requires a generous memory limit to run; somewhere around +200 MB is a good starting point, but considerably more may be needed for +more complex programs. The default -m limit will be automatically bumped up +to 200 MB when specifying -Q to afl-fuzz; be careful when overriding this. + +In principle, if you set CPU_TARGET before calling ./build_qemu_support.sh, +you should get a build capable of running non-native binaries (say, you +can try CPU_TARGET=arm). This is also necessary for running 32-bit binaries +on a 64-bit system (CPU_TARGET=i386). + +Note: if you want the QEMU 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 + +There is ./libcompcov/ which implements laf-intel (splitting memcmp, +strncmp, etc. to make these conditions easier solvable by afl-fuzz). +Highly recommended. + +The option that enables QEMU CompareCoverage is AFL_COMPCOV_LEVEL. +AFL_COMPCOV_LEVEL=1 is to instrument comparisons with only immediate +values / read-only memory. AFL_COMPCOV_LEVEL=2 instruments all +comparison instructions and memory comparison functions when libcompcov +is preloaded. Comparison instructions are currently instrumented only +on the x86 and x86_64 targets. + +Another option is the environment variable AFL_ENTRYPOINT which allows +move the forkserver to a different part, e.g. just before the file is +opened (e.g. way after command line parsing and config file loading, etc) +which can be a huge speed improvement. Note that the specified address +must be an address of a basic block. + +## 4) Notes on linking + +The feature is supported only on Linux. Supporting BSD may amount to porting +the changes made to linux-user/elfload.c and applying them to +bsd-user/elfload.c, but I have not looked into this yet. + +The instrumentation follows only the .text section of the first ELF binary +encountered in the linking process. It does not trace shared libraries. In +practice, this means two things: + + - Any libraries you want to analyze *must* be linked statically into the + executed ELF file (this will usually be the case for closed-source + apps). + + - Standard C libraries and other stuff that is wasteful to instrument + should be linked dynamically - otherwise, AFL will have no way to avoid + peeking into them. + +Setting AFL_INST_LIBS=1 can be used to circumvent the .text detection logic +and instrument every basic block encountered. + +## 5) Benchmarking + +If you want to compare the performance of the QEMU instrumentation with that of +afl-gcc compiled code against the same target, you need to build the +non-instrumented binary with the same optimization flags that are normally +injected by afl-gcc, and make sure that the bits to be tested are statically +linked into the binary. A common way to do this would be: + +$ CFLAGS="-O3 -funroll-loops" ./configure --disable-shared +$ make clean all + +Comparative measurements of execution speed or instrumentation coverage will be +fairly meaningless if the optimization levels or instrumentation scopes don't +match. + +## 6) Gotchas, feedback, bugs + +If you need to fix up checksums or do other cleanup on mutated test cases, see +experimental/post_library/ for a viable solution. + +Do not mix QEMU mode with ASAN, MSAN, or the likes; QEMU doesn't appreciate +the "shadow VM" trick employed by the sanitizers and will probably just +run out of memory. + +Compared to fully-fledged virtualization, the user emulation mode is *NOT* a +security boundary. The binaries can freely interact with the host OS. If you +somehow need to fuzz an untrusted binary, put everything in a sandbox first. + +QEMU does not necessarily support all CPU or hardware features that your +target program may be utilizing. In particular, it does not appear to have +full support for AVX2 / FMA3. Using binaries for older CPUs, or recompiling them +with -march=core2, can help. + +Beyond that, this is an early-stage mechanism, so fields reports are welcome. +You can send them to . + +## 7) Alternatives: static rewriting + +Statically rewriting binaries just once, instead of attempting to translate +them at run time, can be a faster alternative. That said, static rewriting is +fraught with peril, because it depends on being able to properly and fully model +program control flow without actually executing each and every code path. + +The best implementation is this one: + + https://github.com/vanhauser-thc/afl-dyninst + +The issue however is Dyninst which is not rewriting the binaries so that +they run stable. a lot of crashes happen, especially in C++ programs that +use throw/catch. Try it first, and if it works for you be happy as it is +2-3x as fast as qemu_mode. diff --git a/qemu_mode/README.qemu b/qemu_mode/README.qemu deleted file mode 100644 index cd8559ad..00000000 --- a/qemu_mode/README.qemu +++ /dev/null @@ -1,146 +0,0 @@ -========================================================= -High-performance binary-only instrumentation for afl-fuzz -========================================================= - - (See ../docs/README for the general instruction manual.) - -1) Introduction ---------------- - -The code in this directory allows you to build a standalone feature that -leverages the QEMU "user emulation" mode and allows callers to obtain -instrumentation output for black-box, closed-source binaries. This mechanism -can be then used by afl-fuzz to stress-test targets that couldn't be built -with afl-gcc. - -The usual performance cost is 2-5x, which is considerably better than -seen so far in experiments with tools such as DynamoRIO and PIN. - -The idea and much of the initial implementation comes from Andrew Griffiths. -The actual implementation on QEMU 3 (shipped with afl++) is from -Andrea Fioraldi. Special thanks to abiondo that re-enabled TCG chaining. - -2) How to use -------------- - -The feature is implemented with a patch to QEMU 3.1.0. The simplest way -to build it is to run ./build_qemu_support.sh. The script will download, -configure, and compile the QEMU binary for you. - -QEMU is a big project, so this will take a while, and you may have to -resolve a couple of dependencies (most notably, you will definitely need -libtool and glib2-devel). - -Once the binaries are compiled, you can leverage the QEMU tool by calling -afl-fuzz and all the related utilities with -Q in the command line. - -Note that QEMU requires a generous memory limit to run; somewhere around -200 MB is a good starting point, but considerably more may be needed for -more complex programs. The default -m limit will be automatically bumped up -to 200 MB when specifying -Q to afl-fuzz; be careful when overriding this. - -In principle, if you set CPU_TARGET before calling ./build_qemu_support.sh, -you should get a build capable of running non-native binaries (say, you -can try CPU_TARGET=arm). This is also necessary for running 32-bit binaries -on a 64-bit system (CPU_TARGET=i386). - -Note: if you want the QEMU 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 ----------- - -There is ./libcompcov/ which implements laf-intel (splitting memcmp, -strncmp, etc. to make these conditions easier solvable by afl-fuzz). -Highly recommended. - -The option that enables QEMU CompareCoverage is QEMU_COMPCOV_LEVEL. -QEMU_COMPCOV_LEVEL=1 is to instrument comparisons with only immediate -values / read-only memory. QEMU_COMPCOV_LEVEL=2 instruments all -comparison instructions and memory comparison functions when libcompcov -is preloaded. Comparison instructions are currently instrumented only -on the x86 and x86_64 targets. - -Another option is the environment variable AFL_ENTRYPOINT which allows -move the forkserver to a different part, e.g. just before the file is -opened (e.g. way after command line parsing and config file loading, etc) -which can be a huge speed improvement. Note that the specified address -must be an address of a basic block. - -4) Notes on linking -------------------- - -The feature is supported only on Linux. Supporting BSD may amount to porting -the changes made to linux-user/elfload.c and applying them to -bsd-user/elfload.c, but I have not looked into this yet. - -The instrumentation follows only the .text section of the first ELF binary -encountered in the linking process. It does not trace shared libraries. In -practice, this means two things: - - - Any libraries you want to analyze *must* be linked statically into the - executed ELF file (this will usually be the case for closed-source - apps). - - - Standard C libraries and other stuff that is wasteful to instrument - should be linked dynamically - otherwise, AFL will have no way to avoid - peeking into them. - -Setting AFL_INST_LIBS=1 can be used to circumvent the .text detection logic -and instrument every basic block encountered. - -5) Benchmarking ---------------- - -If you want to compare the performance of the QEMU instrumentation with that of -afl-gcc compiled code against the same target, you need to build the -non-instrumented binary with the same optimization flags that are normally -injected by afl-gcc, and make sure that the bits to be tested are statically -linked into the binary. A common way to do this would be: - -$ CFLAGS="-O3 -funroll-loops" ./configure --disable-shared -$ make clean all - -Comparative measurements of execution speed or instrumentation coverage will be -fairly meaningless if the optimization levels or instrumentation scopes don't -match. - -6) Gotchas, feedback, bugs --------------------------- - -If you need to fix up checksums or do other cleanup on mutated test cases, see -experimental/post_library/ for a viable solution. - -Do not mix QEMU mode with ASAN, MSAN, or the likes; QEMU doesn't appreciate -the "shadow VM" trick employed by the sanitizers and will probably just -run out of memory. - -Compared to fully-fledged virtualization, the user emulation mode is *NOT* a -security boundary. The binaries can freely interact with the host OS. If you -somehow need to fuzz an untrusted binary, put everything in a sandbox first. - -QEMU does not necessarily support all CPU or hardware features that your -target program may be utilizing. In particular, it does not appear to have -full support for AVX2 / FMA3. Using binaries for older CPUs, or recompiling them -with -march=core2, can help. - -Beyond that, this is an early-stage mechanism, so fields reports are welcome. -You can send them to . - -7) Alternatives: static rewriting ---------------------------------- - -Statically rewriting binaries just once, instead of attempting to translate -them at run time, can be a faster alternative. That said, static rewriting is -fraught with peril, because it depends on being able to properly and fully model -program control flow without actually executing each and every code path. - -The best implementation is this one: - - https://github.com/vanhauser-thc/afl-dyninst - -The issue however is Dyninst which is not rewriting the binaries so that -they run stable. a lot of crashes happen, especially in C++ programs that -use throw/catch. Try it first, and if it works for you be happy as it is -2-3x as fast as qemu_mode. diff --git a/qemu_mode/build_qemu_support.sh b/qemu_mode/build_qemu_support.sh index 78ad5680..35f5b8ca 100755 --- a/qemu_mode/build_qemu_support.sh +++ b/qemu_mode/build_qemu_support.sh @@ -3,10 +3,17 @@ # american fuzzy lop - QEMU build script # -------------------------------------- # -# Written by Andrew Griffiths and -# Michal Zalewski +# Originally written by Andrew Griffiths and +# Michal Zalewski +# +# TCG instrumentation and block chaining support by Andrea Biondo +# +# +# QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero +# counters by Andrea Fioraldi # # Copyright 2015, 2016, 2017 Google Inc. All rights reserved. +# Copyright 2019 AFLplusplus Project. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. diff --git a/qemu_mode/libcompcov/libcompcov.so.c b/qemu_mode/libcompcov/libcompcov.so.c index 92e4dbaa..0ccda927 100644 --- a/qemu_mode/libcompcov/libcompcov.so.c +++ b/qemu_mode/libcompcov/libcompcov.so.c @@ -5,7 +5,7 @@ Written and maintained by Andrea Fioraldi - Copyright 2019 Andrea Fioraldi. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. diff --git a/qemu_mode/patches/afl-qemu-common.h b/qemu_mode/patches/afl-qemu-common.h index 8013800d..c475cb58 100644 --- a/qemu_mode/patches/afl-qemu-common.h +++ b/qemu_mode/patches/afl-qemu-common.h @@ -1,19 +1,18 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - high-performance binary-only instrumentation + ------------------------------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski - - Idea & design very much by Andrew Griffiths. + Originally written by Andrew Griffiths and + Michal Zalewski TCG instrumentation and block chaining support by Andrea Biondo - QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi - + QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero + counters by Andrea Fioraldi Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. diff --git a/qemu_mode/patches/afl-qemu-cpu-inl.h b/qemu_mode/patches/afl-qemu-cpu-inl.h index 04d9007d..4ad31b60 100644 --- a/qemu_mode/patches/afl-qemu-cpu-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-inl.h @@ -1,19 +1,18 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - high-performance binary-only instrumentation + ------------------------------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski - - Idea & design very much by Andrew Griffiths. + Originally written by Andrew Griffiths and + Michal Zalewski TCG instrumentation and block chaining support by Andrea Biondo - QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi - + QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero + counters by Andrea Fioraldi Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h index fc78e652..09ecb9d2 100644 --- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h @@ -1,19 +1,18 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - high-performance binary-only instrumentation + ------------------------------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski - - Idea & design very much by Andrew Griffiths. + Originally written by Andrew Griffiths and + Michal Zalewski TCG instrumentation and block chaining support by Andrea Biondo - - QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi - + + QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero + counters by Andrea Fioraldi Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. diff --git a/qemu_mode/patches/afl-qemu-tcg-inl.h b/qemu_mode/patches/afl-qemu-tcg-inl.h index ff90d1b9..a9c53b8c 100644 --- a/qemu_mode/patches/afl-qemu-tcg-inl.h +++ b/qemu_mode/patches/afl-qemu-tcg-inl.h @@ -1,19 +1,18 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - high-performance binary-only instrumentation + ------------------------------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski - - Idea & design very much by Andrew Griffiths. + Originally written by Andrew Griffiths and + Michal Zalewski TCG instrumentation and block chaining support by Andrea Biondo - QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi - + QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero + counters by Andrea Fioraldi Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. diff --git a/qemu_mode/patches/afl-qemu-translate-inl.h b/qemu_mode/patches/afl-qemu-translate-inl.h index d63c5167..ffe43dba 100644 --- a/qemu_mode/patches/afl-qemu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-translate-inl.h @@ -1,19 +1,18 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - high-performance binary-only instrumentation + ------------------------------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski - - Idea & design very much by Andrew Griffiths. + Originally written by Andrew Griffiths and + Michal Zalewski TCG instrumentation and block chaining support by Andrea Biondo - QEMU 3.1.0 port, TCG thread-safety and CompareCoverage by Andrea Fioraldi - + QEMU 3.1.0 port, TCG thread-safety, CompareCoverage and NeverZero + counters by Andrea Fioraldi Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. diff --git a/unicorn_mode/README.md b/unicorn_mode/README.md index 9ee975ef..ea3e3c9b 100644 --- a/unicorn_mode/README.md +++ b/unicorn_mode/README.md @@ -1,23 +1,119 @@ -``` - __ _ _ - __ _ / _| | _ _ _ __ (_) ___ ___ _ __ _ __ - / _` | |_| |___| | | | '_ \| |/ __/ _ \| '__| '_ \ -| (_| | _| |___| |_| | | | | | (_| (_) | | | | | | - \__,_|_| |_| \__,_|_| |_|_|\___\___/|_| |_| |_| - -``` +# Unicorn-based binary-only instrumentation for afl-fuzz -afl-unicorn lets you fuzz any piece of binary that can be emulated by -[Unicorn Engine](http://www.unicorn-engine.org/). +The idea and much of the original implementation comes from Nathan Voss . -Requirements: Python2 +The port to afl++ if by Dominik Maier . -For the full readme please see docs/unicorn_mode.txt +The CompareCoverage and NeverZero counters features by Andrea Fioraldi . -For an in-depth description of what this is, how to install it, and how to use -it check out this [blog post](https://medium.com/@njvoss299/afl-unicorn-fuzzing-arbitrary-binary-code-563ca28936bf). +## 1) Introduction -For general help with AFL, please refer to the documents in the ./docs/ directory. +The code in ./unicorn_mode allows you to build a standalone feature that +leverages the Unicorn Engine and allows callers to obtain instrumentation +output for black-box, closed-source binary code snippets. This mechanism +can be then used by afl-fuzz to stress-test targets that couldn't be built +with afl-gcc or used in QEMU mode, or with other extensions such as +TriforceAFL. -Created by Nathan Voss, originally funded by -[Battelle](https://www.battelle.org/cyber). +There is a significant performance penalty compared to native AFL, +but at least we're able to use AFL on these binaries, right? + +## 2) How to use + +Requirements: you need an installed python2 environment. + +### Building AFL's Unicorn Mode + +First, make afl++ as usual. +Once that completes successfully you need to build and add in the Unicorn Mode +features: + + $ cd unicorn_mode + $ ./build_unicorn_support.sh + +NOTE: This script downloads a Unicorn Engine commit that has been tested +and is stable-ish from the Unicorn github page. If you are offline, you'll need +to hack up this script a little bit and supply your own copy of Unicorn's latest +stable release. It's not very hard, just check out the beginning of the +build_unicorn_support.sh script and adjust as necessary. + +Building Unicorn will take a little bit (~5-10 minutes). Once it completes +it automatically compiles a sample application and verify that it works. + +### Fuzzing with Unicorn Mode + +To really use unicorn-mode effectively you need to prepare the following: + + * Relevant binary code to be fuzzed + * Knowledge of the memory map and good starting state + * Folder containing sample inputs to start fuzzing with + + Same ideas as any other AFL inputs + + Quality/speed of results will depend greatly on quality of starting + samples + + See AFL's guidance on how to create a sample corpus + * Unicorn-based test harness which: + + Adds memory map regions + + Loads binary code into memory + + Emulates at least one instruction* + + Yeah, this is lame. See 'Gotchas' section below for more info + + Loads and verifies data to fuzz from a command-line specified file + + AFL will provide mutated inputs by changing the file passed to + the test harness + + Presumably the data to be fuzzed is at a fixed buffer address + + If input constraints (size, invalid bytes, etc.) are known they + should be checked after the file is loaded. If a constraint + fails, just exit the test harness. AFL will treat the input as + 'uninteresting' and move on. + + Sets up registers and memory state for beginning of test + + Emulates the interested code from beginning to end + + If a crash is detected, the test harness must 'crash' by + throwing a signal (SIGSEGV, SIGKILL, SIGABORT, etc.) + +Once you have all those things ready to go you just need to run afl-fuzz in +'unicorn-mode' by passing in the '-U' flag: + + $ afl-fuzz -U -m none -i /path/to/inputs -o /path/to/results -- ./test_harness @@ + +The normal afl-fuzz command line format applies to everything here. Refer to +AFL's main documentation for more info about how to use afl-fuzz effectively. + +For a much clearer vision of what all of this looks like, please refer to the +sample provided in the 'unicorn_mode/samples' directory. There is also a blog +post that goes over the basics at: + +https://medium.com/@njvoss299/afl-unicorn-fuzzing-arbitrary-binary-code-563ca28936bf + +The 'helper_scripts' directory also contains several helper scripts that allow you +to dump context from a running process, load it, and hook heap allocations. For details +on how to use this check out the follow-up blog post to the one linked above. + +A example use of AFL-Unicorn mode is discussed in the Paper Unicorefuzz: +https://www.usenix.org/conference/woot19/presentation/maier + +## 3) Options + +As for the QEMU-based instrumentation, the afl-unicorn twist of afl++ +comes with a sub-instruction based instrumentation similar in purpose to laf-intel. + +The options that enables Unicorn CompareCoverage are the same used for QEMU. +AFL_COMPCOV_LEVEL=1 is to instrument comparisons with only immediate +values. QEMU_COMPCOV_LEVEL=2 instruments all +comparison instructions. Comparison instructions are currently instrumented only +on the x86 and x86_64 targets. + +## 4) Gotchas, feedback, bugs + +To make sure that AFL's fork server starts up correctly the Unicorn test +harness script must emulate at least one instruction before loading the +data that will be fuzzed from the input file. It doesn't matter what the +instruction is, nor if it is valid. This is an artifact of how the fork-server +is started and could likely be fixed with some clever re-arranging of the +patches applied to Unicorn. + +Running the build script builds Unicorn and its python bindings and installs +them on your system. This installation will supersede any existing Unicorn +installation with the patched afl-unicorn version. + +Refer to the unicorn_mode/samples/arm_example/arm_tester.c for an example +of how to do this properly! If you don't get this right, AFL will not +load any mutated inputs and your fuzzing will be useless! diff --git a/unicorn_mode/build_unicorn_support.sh b/unicorn_mode/build_unicorn_support.sh index 2c0fe4b1..1575f66c 100755 --- a/unicorn_mode/build_unicorn_support.sh +++ b/unicorn_mode/build_unicorn_support.sh @@ -1,16 +1,20 @@ #!/bin/sh # -# american fuzzy lop - Unicorn-Mode build script -# -------------------------------------- +# american fuzzy lop++ - unicorn mode build script +# ------------------------------------------------ # -# Written by Nathan Voss +# Originally written by Nathan Voss # # Adapted from code by Andrew Griffiths and # Michal Zalewski # -# Adapted for Afl++ by Dominik Maier +# Adapted for AFLplusplus by Dominik Maier +# +# CompareCoverage and NeverZero counters by Andrea Fioraldi +# # # Copyright 2017 Battelle Memorial Institute. All rights reserved. +# Copyright 2019 AFLplusplus Project. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. diff --git a/unicorn_mode/patches/afl-unicorn-common.h b/unicorn_mode/patches/afl-unicorn-common.h index 9a1b2a6c..6798832c 100644 --- a/unicorn_mode/patches/afl-unicorn-common.h +++ b/unicorn_mode/patches/afl-unicorn-common.h @@ -1,17 +1,17 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - unicorn instrumentation + ---------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski + Originally written by Andrew Griffiths and + Michal Zalewski - TCG instrumentation and block chaining support by Andrea Biondo - Adapted for afl-unicorn by Dominik Maier - Idea & design very much by Andrew Griffiths. + CompareCoverage and NeverZero counters by Andrea Fioraldi + - Copyright 2015, 2016 Google Inc. All rights reserved. + Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. @@ -24,7 +24,7 @@ to implement AFL-style instrumentation and to take care of the remaining parts of the AFL fork server logic. - The resulting QEMU binary is essentially a standalone instrumentation + The resulting libunicorn binary is essentially a standalone instrumentation tool; for an example of how to leverage it for other purposes, you can have a look at afl-showmap.c. diff --git a/unicorn_mode/patches/afl-unicorn-cpu-inl.h b/unicorn_mode/patches/afl-unicorn-cpu-inl.h index 90937a17..a713e4ca 100644 --- a/unicorn_mode/patches/afl-unicorn-cpu-inl.h +++ b/unicorn_mode/patches/afl-unicorn-cpu-inl.h @@ -1,17 +1,17 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - unicorn instrumentation + ---------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski + Originally written by Andrew Griffiths and + Michal Zalewski - TCG instrumentation and block chaining support by Andrea Biondo - Adapted for afl-unicorn by Dominik Maier - Idea & design very much by Andrew Griffiths. + CompareCoverage and NeverZero counters by Andrea Fioraldi + - Copyright 2015, 2016 Google Inc. All rights reserved. + Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. @@ -24,7 +24,7 @@ to implement AFL-style instrumentation and to take care of the remaining parts of the AFL fork server logic. - The resulting QEMU binary is essentially a standalone instrumentation + The resulting libunicorn binary is essentially a standalone instrumentation tool; for an example of how to leverage it for other purposes, you can have a look at afl-showmap.c. diff --git a/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h b/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h index 7e8f47c9..69877c6b 100644 --- a/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h +++ b/unicorn_mode/patches/afl-unicorn-cpu-translate-inl.h @@ -1,17 +1,17 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - unicorn instrumentation + ---------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski + Originally written by Andrew Griffiths and + Michal Zalewski - TCG instrumentation and block chaining support by Andrea Biondo - Adapted for afl-unicorn by Dominik Maier - Idea & design very much by Andrew Griffiths. + CompareCoverage and NeverZero counters by Andrea Fioraldi + - Copyright 2015, 2016 Google Inc. All rights reserved. + Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. @@ -24,7 +24,7 @@ to implement AFL-style instrumentation and to take care of the remaining parts of the AFL fork server logic. - The resulting QEMU binary is essentially a standalone instrumentation + The resulting libunicorn binary is essentially a standalone instrumentation tool; for an example of how to leverage it for other purposes, you can have a look at afl-showmap.c. diff --git a/unicorn_mode/patches/afl-unicorn-tcg-op-inl.h b/unicorn_mode/patches/afl-unicorn-tcg-op-inl.h index d5a29cce..fa4974d6 100644 --- a/unicorn_mode/patches/afl-unicorn-tcg-op-inl.h +++ b/unicorn_mode/patches/afl-unicorn-tcg-op-inl.h @@ -1,17 +1,17 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - unicorn instrumentation + ---------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski + Originally written by Andrew Griffiths and + Michal Zalewski - TCG instrumentation and block chaining support by Andrea Biondo - Adapted for afl-unicorn by Dominik Maier - Idea & design very much by Andrew Griffiths. + CompareCoverage and NeverZero counters by Andrea Fioraldi + - Copyright 2015, 2016 Google Inc. All rights reserved. + Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. @@ -24,7 +24,7 @@ to implement AFL-style instrumentation and to take care of the remaining parts of the AFL fork server logic. - The resulting QEMU binary is essentially a standalone instrumentation + The resulting libunicorn binary is essentially a standalone instrumentation tool; for an example of how to leverage it for other purposes, you can have a look at afl-showmap.c. diff --git a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h index 0019bbfa..1f0667ce 100644 --- a/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h +++ b/unicorn_mode/patches/afl-unicorn-tcg-runtime-inl.h @@ -1,17 +1,17 @@ /* - american fuzzy lop - high-performance binary-only instrumentation - ----------------------------------------------------------------- + american fuzzy lop++ - unicorn instrumentation + ---------------------------------------------- - Written by Andrew Griffiths and - Michal Zalewski + Originally written by Andrew Griffiths and + Michal Zalewski - TCG instrumentation and block chaining support by Andrea Biondo - Adapted for afl-unicorn by Dominik Maier - Idea & design very much by Andrew Griffiths. + CompareCoverage and NeverZero counters by Andrea Fioraldi + - Copyright 2015, 2016 Google Inc. All rights reserved. + Copyright 2015, 2016, 2017 Google Inc. All rights reserved. + Copyright 2019 AFLplusplus Project. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. @@ -24,7 +24,7 @@ to implement AFL-style instrumentation and to take care of the remaining parts of the AFL fork server logic. - The resulting QEMU binary is essentially a standalone instrumentation + The resulting libunicorn binary is essentially a standalone instrumentation tool; for an example of how to leverage it for other purposes, you can have a look at afl-showmap.c. diff --git a/unicorn_mode/samples/compcov_x64/COMPILE.md b/unicorn_mode/samples/compcov_x64/COMPILE.md index db488d30..35de7ad8 100644 --- a/unicorn_mode/samples/compcov_x64/COMPILE.md +++ b/unicorn_mode/samples/compcov_x64/COMPILE.md @@ -1,5 +1,4 @@ -Compiling compcov_target.c -========================== +# Compiling compcov_target.c compcov_target.c was compiled without optimization, position-independent, and without standard libraries using the following command line: diff --git a/unicorn_mode/samples/compcov_x64/compcov_target.c b/unicorn_mode/samples/compcov_x64/compcov_target.c index 71b4cb0e..eb1205b1 100644 --- a/unicorn_mode/samples/compcov_x64/compcov_target.c +++ b/unicorn_mode/samples/compcov_x64/compcov_target.c @@ -7,7 +7,7 @@ * (0x00300000), so make sure that your Unicorn emulation of this * puts user data there. * - * Written by Nathan Voss + * Written by Andrea Fioraldi */ // Magic address where mutated data will be placed diff --git a/unicorn_mode/samples/simple/COMPILE.md b/unicorn_mode/samples/simple/COMPILE.md index bd4a66c6..f7bf5b50 100644 --- a/unicorn_mode/samples/simple/COMPILE.md +++ b/unicorn_mode/samples/simple/COMPILE.md @@ -1,5 +1,4 @@ -Compiling simple_target.c -========================== +# Compiling simple_target.c You shouldn't need to compile simple_target.c since a MIPS binary version is pre-built and shipped with afl-unicorn. This file documents how the binary @@ -38,4 +37,4 @@ mips-linux-gnu-gcc -o simple_target.elf simple_target.c -fPIC -O0 -nostdlib Note that the output of this is padded with nulls for 16-byte alignment. This is important when emulating it, as NOPs will be added after the return of main() -as necessary. \ No newline at end of file +as necessary. -- cgit 1.4.1