From bca7ce804308fdc24404d26a02d2e10116ef6289 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 1 Jun 2020 12:30:20 +0200 Subject: [PATCH 1/7] fixed persistent mode shared mem fuzzing --- examples/persistent_demo/Makefile | 6 +- examples/persistent_demo/persistent_demo.c | 1 + .../persistent_demo/persistent_demo_new.c | 1 + examples/persistent_demo/test-instr.c | 60 +++++++++++++++++++ llvm_mode/GNUmakefile | 9 ++- llvm_mode/afl-llvm-rt.o.c | 44 +++++++++++++- 6 files changed, 116 insertions(+), 5 deletions(-) create mode 100644 examples/persistent_demo/test-instr.c diff --git a/examples/persistent_demo/Makefile b/examples/persistent_demo/Makefile index cbbb7239..ea8fd02a 100644 --- a/examples/persistent_demo/Makefile +++ b/examples/persistent_demo/Makefile @@ -1,6 +1,10 @@ all: afl-clang-fast -o persistent_demo persistent_demo.c afl-clang-fast -o persistent_demo_new persistent_demo_new.c + afl-clang-fast -o test-instr test-instr.c + +document: + afl-clang-fast -D_AFL_DOCUMENT_MUTATIONS -o test-instr test-instr.c clean: - rm -f persistent_demo persistent_demo_new + rm -f persistent_demo persistent_demo_new test-instr diff --git a/examples/persistent_demo/persistent_demo.c b/examples/persistent_demo/persistent_demo.c index 2da49bb0..4cedc32c 100644 --- a/examples/persistent_demo/persistent_demo.c +++ b/examples/persistent_demo/persistent_demo.c @@ -41,6 +41,7 @@ int main(int argc, char **argv) { terminate normally. This limits the impact of accidental memory leaks and similar hiccups. */ + __AFL_INIT(); while (__AFL_LOOP(1000)) { /*** PLACEHOLDER CODE ***/ diff --git a/examples/persistent_demo/persistent_demo_new.c b/examples/persistent_demo/persistent_demo_new.c index 36411e13..69468bdd 100644 --- a/examples/persistent_demo/persistent_demo_new.c +++ b/examples/persistent_demo/persistent_demo_new.c @@ -42,6 +42,7 @@ int main(int argc, char **argv) { terminate normally. This limits the impact of accidental memory leaks and similar hiccups. */ + __AFL_INIT(); buf = __AFL_FUZZ_TESTCASE_BUF; while (__AFL_LOOP(1000)) { diff --git a/examples/persistent_demo/test-instr.c b/examples/persistent_demo/test-instr.c new file mode 100644 index 00000000..069e74dd --- /dev/null +++ b/examples/persistent_demo/test-instr.c @@ -0,0 +1,60 @@ +/* + american fuzzy lop++ - a trivial program to test the build + -------------------------------------------------------- + Originally written by Michal Zalewski + Copyright 2014 Google Inc. All rights reserved. + Copyright 2019-2020 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. + You may obtain a copy of the License at: + http://www.apache.org/licenses/LICENSE-2.0 + */ + +#include +#include +#include +#include +#include +#include +#include + +__AFL_FUZZ_INIT(); + +int main(int argc, char **argv) { + + __AFL_INIT(); + unsigned char *buf = __AFL_FUZZ_TESTCASE_BUF; + + while(__AFL_LOOP(2147483647)) { + + unsigned int len = __AFL_FUZZ_TESTCASE_LEN; + +#ifdef _AFL_DOCUMENT_MUTATIONS + static unsigned int counter = 0; + char fn[32]; + sprintf(fn, "%09u:test-instr", counter); + int fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); + if (fd_doc >= 0) { + if (write(fd_doc, __afl_fuzz_ptr, __afl_fuzz_len) != __afl_fuzz_len) { + fprintf(stderr, "write of mutation file failed: %s\n", fn); + unlink(fn); + } + close(fd_doc); + } + counter++; +#endif + + if (!len) continue; + + if (buf[0] == '0') + printf("Looks like a zero to me!\n"); + else if (buf[0] == '1') + printf("Pretty sure that is a one!\n"); + else + printf("Neither one or zero? How quaint!\n"); + } + + return 0; + +} + diff --git a/llvm_mode/GNUmakefile b/llvm_mode/GNUmakefile index 50a6be2b..0666fde0 100644 --- a/llvm_mode/GNUmakefile +++ b/llvm_mode/GNUmakefile @@ -354,16 +354,21 @@ endif ../cmplog-instructions-pass.so: cmplog-instructions-pass.cc afl-llvm-common.o | test_deps $(CXX) $(CLANG_CFL) -shared $< -o $@ $(CLANG_LFL) afl-llvm-common.o +document: + $(CLANG_BIN) -D_AFL_DOCUMENT_MUTATIONS $(CFLAGS) -Wno-unused-result -fPIC -c afl-llvm-rt.o.c -o ../afl-llvm-rt.o + @$(CLANG_BIN) -D_AFL_DOCUMENT_MUTATIONS $(CFLAGS) -Wno-unused-result -m32 -fPIC -c afl-llvm-rt.o.c -o ../afl-llvm-rt-32.o 2>/dev/null; if [ "$$?" = "0" ]; then echo "success!"; else echo "failed (that's fine)"; fi + @$(CLANG_BIN) -D_AFL_DOCUMENT_MUTATIONS $(CFLAGS) -Wno-unused-result -m64 -fPIC -c afl-llvm-rt.o.c -o ../afl-llvm-rt-64.o 2>/dev/null; if [ "$$?" = "0" ]; then echo "success!"; else echo "failed (that's fine)"; fi + ../afl-llvm-rt.o: afl-llvm-rt.o.c | test_deps $(CLANG_BIN) $(CFLAGS) -Wno-unused-result -fPIC -c $< -o $@ ../afl-llvm-rt-32.o: afl-llvm-rt.o.c | test_deps @printf "[*] Building 32-bit variant of the runtime (-m32)... " - @$(CC_SAVE) $(CFLAGS) -Wno-unused-result -m32 -fPIC -c $< -o $@ 2>/dev/null; if [ "$$?" = "0" ]; then echo "success!"; else echo "failed (that's fine)"; fi + @$(CLANG_BIN) $(CFLAGS) -Wno-unused-result -m32 -fPIC -c $< -o $@ 2>/dev/null; if [ "$$?" = "0" ]; then echo "success!"; else echo "failed (that's fine)"; fi ../afl-llvm-rt-64.o: afl-llvm-rt.o.c | test_deps @printf "[*] Building 64-bit variant of the runtime (-m64)... " - @$(CC_SAVE) $(CFLAGS) -Wno-unused-result -m64 -fPIC -c $< -o $@ 2>/dev/null; if [ "$$?" = "0" ]; then echo "success!"; else echo "failed (that's fine)"; fi + @$(CLANG_BIN) $(CFLAGS) -Wno-unused-result -m64 -fPIC -c $< -o $@ 2>/dev/null; if [ "$$?" = "0" ]; then echo "success!"; else echo "failed (that's fine)"; fi test_build: $(PROGS) @echo "[*] Testing the CC wrapper and instrumentation output..." diff --git a/llvm_mode/afl-llvm-rt.o.c b/llvm_mode/afl-llvm-rt.o.c index 3a0584e4..7a763f1b 100644 --- a/llvm_mode/afl-llvm-rt.o.c +++ b/llvm_mode/afl-llvm-rt.o.c @@ -78,6 +78,8 @@ u8 *__afl_area_ptr = __afl_area_initial; u8 *__afl_dictionary; u8 *__afl_fuzz_ptr; u32 __afl_fuzz_len; +u32 __afl_fuzz_len_dummy; +u32 *__afl_fuzz_len_shmem = &__afl_fuzz_len_dummy; u32 __afl_final_loc; u32 __afl_map_size = MAP_SIZE; @@ -163,6 +165,8 @@ static void __afl_map_shm_fuzz() { exit(1); } + + __afl_fuzz_len_shmem = (u32*) mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); } @@ -443,9 +447,26 @@ static void __afl_start_snapshots(void) { } - __afl_fuzz_len = (was_killed >> 8); + *__afl_fuzz_len_shmem = __afl_fuzz_len = (was_killed >> 8); was_killed = (was_killed & 0xff); +#ifdef _AFL_DOCUMENT_MUTATIONS + if (__afl_fuzz_ptr) { + static uint32_t counter = 0; + char fn[32]; + sprintf(fn, "%09u:forkserver", counter); + s32 fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); + if (fd_doc >= 0) { + if (write(fd_doc, __afl_fuzz_ptr, __afl_fuzz_len) != __afl_fuzz_len) { + fprintf(stderr, "write of mutation file failed: %s\n", fn); + unlink(fn); + } + close(fd_doc); + } + counter++; + } +#endif + /* If we stopped the child in persistent mode, but there was a race condition and afl-fuzz already issued SIGKILL, write off the old process. */ @@ -620,9 +641,26 @@ static void __afl_start_forkserver(void) { } - __afl_fuzz_len = (was_killed >> 8); + *__afl_fuzz_len_shmem = __afl_fuzz_len = (was_killed >> 8); was_killed = (was_killed & 0xff); +#ifdef _AFL_DOCUMENT_MUTATIONS + if (__afl_fuzz_ptr) { + static uint32_t counter = 0; + char fn[32]; + sprintf(fn, "%09u:forkserver", counter); + s32 fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); + if (fd_doc >= 0) { + if (write(fd_doc, __afl_fuzz_ptr, __afl_fuzz_len) != __afl_fuzz_len) { + fprintf(stderr, "write of mutation file failed: %s\n", fn); + unlink(fn); + } + close(fd_doc); + } + counter++; + } +#endif + /* If we stopped the child in persistent mode, but there was a race condition and afl-fuzz already issued SIGKILL, write off the old process. */ @@ -719,6 +757,8 @@ int __afl_persistent_loop(unsigned int max_cnt) { raise(SIGSTOP); + __afl_fuzz_len = *__afl_fuzz_len_shmem; + __afl_area_ptr[0] = 1; memset(__afl_prev_loc, 0, NGRAM_SIZE_MAX * sizeof(PREV_LOC_T)); From 0de25f08ba2e39f680a1440e9b84ee9cf4136f9a Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 1 Jun 2020 12:30:55 +0200 Subject: [PATCH 2/7] code format --- examples/persistent_demo/test-instr.c | 17 +++++++---- llvm_mode/afl-llvm-rt.o.c | 41 ++++++++++++++++++++------- src/afl-fuzz-init.c | 2 -- src/afl-fuzz.c | 6 +--- 4 files changed, 43 insertions(+), 23 deletions(-) diff --git a/examples/persistent_demo/test-instr.c b/examples/persistent_demo/test-instr.c index 069e74dd..cd1c9b0e 100644 --- a/examples/persistent_demo/test-instr.c +++ b/examples/persistent_demo/test-instr.c @@ -24,34 +24,41 @@ int main(int argc, char **argv) { __AFL_INIT(); unsigned char *buf = __AFL_FUZZ_TESTCASE_BUF; - - while(__AFL_LOOP(2147483647)) { - + + while (__AFL_LOOP(2147483647)) { + unsigned int len = __AFL_FUZZ_TESTCASE_LEN; #ifdef _AFL_DOCUMENT_MUTATIONS static unsigned int counter = 0; - char fn[32]; + char fn[32]; sprintf(fn, "%09u:test-instr", counter); int fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd_doc >= 0) { + if (write(fd_doc, __afl_fuzz_ptr, __afl_fuzz_len) != __afl_fuzz_len) { + fprintf(stderr, "write of mutation file failed: %s\n", fn); unlink(fn); + } + close(fd_doc); + } + counter++; #endif if (!len) continue; - + if (buf[0] == '0') printf("Looks like a zero to me!\n"); else if (buf[0] == '1') printf("Pretty sure that is a one!\n"); else printf("Neither one or zero? How quaint!\n"); + } return 0; diff --git a/llvm_mode/afl-llvm-rt.o.c b/llvm_mode/afl-llvm-rt.o.c index 7a763f1b..b96ca7f4 100644 --- a/llvm_mode/afl-llvm-rt.o.c +++ b/llvm_mode/afl-llvm-rt.o.c @@ -74,11 +74,11 @@ u8 __afl_area_initial[MAP_INITIAL_SIZE]; #else u8 __afl_area_initial[MAP_SIZE]; #endif -u8 *__afl_area_ptr = __afl_area_initial; -u8 *__afl_dictionary; -u8 *__afl_fuzz_ptr; -u32 __afl_fuzz_len; -u32 __afl_fuzz_len_dummy; +u8 * __afl_area_ptr = __afl_area_initial; +u8 * __afl_dictionary; +u8 * __afl_fuzz_ptr; +u32 __afl_fuzz_len; +u32 __afl_fuzz_len_dummy; u32 *__afl_fuzz_len_shmem = &__afl_fuzz_len_dummy; u32 __afl_final_loc; @@ -165,8 +165,9 @@ static void __afl_map_shm_fuzz() { exit(1); } - - __afl_fuzz_len_shmem = (u32*) mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); + + __afl_fuzz_len_shmem = (u32 *)mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1, 0); } @@ -450,22 +451,31 @@ static void __afl_start_snapshots(void) { *__afl_fuzz_len_shmem = __afl_fuzz_len = (was_killed >> 8); was_killed = (was_killed & 0xff); -#ifdef _AFL_DOCUMENT_MUTATIONS + #ifdef _AFL_DOCUMENT_MUTATIONS if (__afl_fuzz_ptr) { + static uint32_t counter = 0; - char fn[32]; + char fn[32]; sprintf(fn, "%09u:forkserver", counter); s32 fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd_doc >= 0) { + if (write(fd_doc, __afl_fuzz_ptr, __afl_fuzz_len) != __afl_fuzz_len) { + fprintf(stderr, "write of mutation file failed: %s\n", fn); unlink(fn); + } + close(fd_doc); + } + counter++; + } -#endif + + #endif /* If we stopped the child in persistent mode, but there was a race condition and afl-fuzz already issued SIGKILL, write off the old @@ -646,19 +656,28 @@ static void __afl_start_forkserver(void) { #ifdef _AFL_DOCUMENT_MUTATIONS if (__afl_fuzz_ptr) { + static uint32_t counter = 0; - char fn[32]; + char fn[32]; sprintf(fn, "%09u:forkserver", counter); s32 fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd_doc >= 0) { + if (write(fd_doc, __afl_fuzz_ptr, __afl_fuzz_len) != __afl_fuzz_len) { + fprintf(stderr, "write of mutation file failed: %s\n", fn); unlink(fn); + } + close(fd_doc); + } + counter++; + } + #endif /* If we stopped the child in persistent mode, but there was a race diff --git a/src/afl-fuzz-init.c b/src/afl-fuzz-init.c index 840b57f4..ea281b7b 100644 --- a/src/afl-fuzz-init.c +++ b/src/afl-fuzz-init.c @@ -1949,7 +1949,6 @@ static void handle_skipreq(int sig) { } - /* Setup shared map for fuzzing with input via sharedmem */ void setup_testcase_shmem(afl_state_t *afl) { @@ -1978,7 +1977,6 @@ void setup_testcase_shmem(afl_state_t *afl) { } - /* Do a PATH search and find target binary to see that it exists and isn't a shell script - a common and painful mistake. We also check for a valid ELF header and for evidence of AFL instrumentation. */ diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c index 1c797424..54d59a9b 100644 --- a/src/afl-fuzz.c +++ b/src/afl-fuzz.c @@ -1179,11 +1179,7 @@ int main(int argc, char **argv_orig, char **envp) { check_binary(afl, argv[optind]); - if (afl->shmem_testcase_mode) { - - setup_testcase_shmem(afl); - - } + if (afl->shmem_testcase_mode) { setup_testcase_shmem(afl); } afl->start_time = get_cur_time(); From 15c0ad60c530906131fc089d8f5b05710c69f109 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 1 Jun 2020 13:15:16 +0200 Subject: [PATCH 3/7] minimal changes to a test --- examples/persistent_demo/Makefile | 2 +- examples/persistent_demo/test-instr.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/examples/persistent_demo/Makefile b/examples/persistent_demo/Makefile index ea8fd02a..e2cf97f5 100644 --- a/examples/persistent_demo/Makefile +++ b/examples/persistent_demo/Makefile @@ -4,7 +4,7 @@ all: afl-clang-fast -o test-instr test-instr.c document: - afl-clang-fast -D_AFL_DOCUMENT_MUTATIONS -o test-instr test-instr.c + AFL_DONT_OPTIMIZE=1 afl-clang-fast -D_AFL_DOCUMENT_MUTATIONS -o test-instr test-instr.c clean: rm -f persistent_demo persistent_demo_new test-instr diff --git a/examples/persistent_demo/test-instr.c b/examples/persistent_demo/test-instr.c index cd1c9b0e..4cd07102 100644 --- a/examples/persistent_demo/test-instr.c +++ b/examples/persistent_demo/test-instr.c @@ -36,7 +36,7 @@ int main(int argc, char **argv) { int fd_doc = open(fn, O_WRONLY | O_CREAT | O_TRUNC, 0600); if (fd_doc >= 0) { - if (write(fd_doc, __afl_fuzz_ptr, __afl_fuzz_len) != __afl_fuzz_len) { + if (write(fd_doc, buf, len) != __afl_fuzz_len) { fprintf(stderr, "write of mutation file failed: %s\n", fn); unlink(fn); From ac998e9222c5a7572716cd2ec1affd00d7a45e3d Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 1 Jun 2020 13:15:34 +0200 Subject: [PATCH 4/7] minimal changes to a test --- examples/persistent_demo/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/examples/persistent_demo/Makefile b/examples/persistent_demo/Makefile index e2cf97f5..6fa1c30e 100644 --- a/examples/persistent_demo/Makefile +++ b/examples/persistent_demo/Makefile @@ -1,7 +1,7 @@ all: afl-clang-fast -o persistent_demo persistent_demo.c afl-clang-fast -o persistent_demo_new persistent_demo_new.c - afl-clang-fast -o test-instr test-instr.c + AFL_DONT_OPTIMIZE=1 afl-clang-fast -o test-instr test-instr.c document: AFL_DONT_OPTIMIZE=1 afl-clang-fast -D_AFL_DOCUMENT_MUTATIONS -o test-instr test-instr.c From 9a65fe904dd0895b9f7d27aae1fbce22fcb598ef Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 1 Jun 2020 13:37:50 +0200 Subject: [PATCH 5/7] small changes to libfuzzer driver --- examples/aflpp_driver/aflpp_driver.cpp | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/examples/aflpp_driver/aflpp_driver.cpp b/examples/aflpp_driver/aflpp_driver.cpp index 3dcc8c3c..a6b168cd 100644 --- a/examples/aflpp_driver/aflpp_driver.cpp +++ b/examples/aflpp_driver/aflpp_driver.cpp @@ -252,27 +252,27 @@ int main(int argc, char **argv) { else if(argc == 2 && (N = atoi(argv[1])) > 0) Printf("WARNING: using the deprecated call style `%s %d`\n", argv[0], N); else if (argc > 1) { - if (!getenv("AFL_DRIVER_DONT_DEFER")) { +// if (!getenv("AFL_DRIVER_DONT_DEFER")) { __afl_sharedmem_fuzzing = 0; __afl_manual_init(); - } +// } return ExecuteFilesOnyByOne(argc, argv); exit(0); } assert(N > 0); - if (!getenv("AFL_DRIVER_DONT_DEFER")) - __afl_manual_init(); - // Call LLVMFuzzerTestOneInput here so that coverage caused by initialization // on the first execution of LLVMFuzzerTestOneInput is ignored. uint8_t dummy_input[1] = {0}; LLVMFuzzerTestOneInput(dummy_input, 1); +// if (!getenv("AFL_DRIVER_DONT_DEFER")) + __afl_manual_init(); + int num_runs = 0; while (__afl_persistent_loop(N)) { - if (__afl_fuzz_len > 0) { + if (__afl_fuzz_len) { num_runs++; LLVMFuzzerTestOneInput(__afl_fuzz_ptr, __afl_fuzz_len); } From adcffce0a083cf32ea41f5631ec0e9d77dfdd115 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 1 Jun 2020 14:57:05 +0200 Subject: [PATCH 6/7] fix libfuzzer driver --- examples/aflpp_driver/aflpp_driver.cpp | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/examples/aflpp_driver/aflpp_driver.cpp b/examples/aflpp_driver/aflpp_driver.cpp index a6b168cd..1feae1c3 100644 --- a/examples/aflpp_driver/aflpp_driver.cpp +++ b/examples/aflpp_driver/aflpp_driver.cpp @@ -262,14 +262,14 @@ int main(int argc, char **argv) { assert(N > 0); - // Call LLVMFuzzerTestOneInput here so that coverage caused by initialization - // on the first execution of LLVMFuzzerTestOneInput is ignored. - uint8_t dummy_input[1] = {0}; - LLVMFuzzerTestOneInput(dummy_input, 1); - // if (!getenv("AFL_DRIVER_DONT_DEFER")) __afl_manual_init(); + // Call LLVMFuzzerTestOneInput here so that coverage caused by initialization + // on the first execution of LLVMFuzzerTestOneInput is ignored. + //uint8_t dummy_input[1] = {0}; + //LLVMFuzzerTestOneInput(dummy_input, 1); + int num_runs = 0; while (__afl_persistent_loop(N)) { if (__afl_fuzz_len) { From 1d15048f2f79bb6836e8a50676a8ecc8cff1e5d0 Mon Sep 17 00:00:00 2001 From: van Hauser Date: Mon, 1 Jun 2020 15:30:44 +0200 Subject: [PATCH 7/7] hopeful finally change for libfuzzer driver --- examples/aflpp_driver/aflpp_driver.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/examples/aflpp_driver/aflpp_driver.cpp b/examples/aflpp_driver/aflpp_driver.cpp index 1feae1c3..f2c604da 100644 --- a/examples/aflpp_driver/aflpp_driver.cpp +++ b/examples/aflpp_driver/aflpp_driver.cpp @@ -267,8 +267,8 @@ int main(int argc, char **argv) { // Call LLVMFuzzerTestOneInput here so that coverage caused by initialization // on the first execution of LLVMFuzzerTestOneInput is ignored. - //uint8_t dummy_input[1] = {0}; - //LLVMFuzzerTestOneInput(dummy_input, 1); + uint8_t dummy_input[1] = {0}; + LLVMFuzzerTestOneInput(dummy_input, 1); int num_runs = 0; while (__afl_persistent_loop(N)) {