diff options
Diffstat (limited to 'examples/aflpp_driver')
| -rw-r--r-- | examples/aflpp_driver/aflpp_driver.c | 168 | ||||
| -rw-r--r-- | examples/aflpp_driver/aflpp_driver_test.c | 16 |
2 files changed, 112 insertions, 72 deletions
diff --git a/examples/aflpp_driver/aflpp_driver.c b/examples/aflpp_driver/aflpp_driver.c index eca3dcd1..86c7a69f 100644 --- a/examples/aflpp_driver/aflpp_driver.c +++ b/examples/aflpp_driver/aflpp_driver.c @@ -14,12 +14,15 @@ cat << EOF > test_fuzzer.cc #include <stddef.h> #include <stdint.h> extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { + if (size > 0 && data[0] == 'H') if (size > 1 && data[1] == 'I') if (size > 2 && data[2] == '!') __builtin_trap(); return 0; + } + EOF # Build your target with -fsanitize-coverage=trace-pc-guard using fresh clang. clang -g -fsanitize-coverage=trace-pc-guard test_fuzzer.cc -c @@ -57,46 +60,46 @@ If 1, close stdout at startup. If 2 close stderr; if 3 close both. #include "config.h" #ifdef _DEBUG -#include "hash.h" + #include "hash.h" #endif // Platform detection. Copied from FuzzerInternal.h #ifdef __linux__ -#define LIBFUZZER_LINUX 1 -#define LIBFUZZER_APPLE 0 -#define LIBFUZZER_NETBSD 0 -#define LIBFUZZER_FREEBSD 0 -#define LIBFUZZER_OPENBSD 0 + #define LIBFUZZER_LINUX 1 + #define LIBFUZZER_APPLE 0 + #define LIBFUZZER_NETBSD 0 + #define LIBFUZZER_FREEBSD 0 + #define LIBFUZZER_OPENBSD 0 #elif __APPLE__ -#define LIBFUZZER_LINUX 0 -#define LIBFUZZER_APPLE 1 -#define LIBFUZZER_NETBSD 0 -#define LIBFUZZER_FREEBSD 0 -#define LIBFUZZER_OPENBSD 0 + #define LIBFUZZER_LINUX 0 + #define LIBFUZZER_APPLE 1 + #define LIBFUZZER_NETBSD 0 + #define LIBFUZZER_FREEBSD 0 + #define LIBFUZZER_OPENBSD 0 #elif __NetBSD__ -#define LIBFUZZER_LINUX 0 -#define LIBFUZZER_APPLE 0 -#define LIBFUZZER_NETBSD 1 -#define LIBFUZZER_FREEBSD 0 -#define LIBFUZZER_OPENBSD 0 + #define LIBFUZZER_LINUX 0 + #define LIBFUZZER_APPLE 0 + #define LIBFUZZER_NETBSD 1 + #define LIBFUZZER_FREEBSD 0 + #define LIBFUZZER_OPENBSD 0 #elif __FreeBSD__ -#define LIBFUZZER_LINUX 0 -#define LIBFUZZER_APPLE 0 -#define LIBFUZZER_NETBSD 0 -#define LIBFUZZER_FREEBSD 1 -#define LIBFUZZER_OPENBSD 0 + #define LIBFUZZER_LINUX 0 + #define LIBFUZZER_APPLE 0 + #define LIBFUZZER_NETBSD 0 + #define LIBFUZZER_FREEBSD 1 + #define LIBFUZZER_OPENBSD 0 #elif __OpenBSD__ -#define LIBFUZZER_LINUX 0 -#define LIBFUZZER_APPLE 0 -#define LIBFUZZER_NETBSD 0 -#define LIBFUZZER_FREEBSD 0 -#define LIBFUZZER_OPENBSD 1 + #define LIBFUZZER_LINUX 0 + #define LIBFUZZER_APPLE 0 + #define LIBFUZZER_NETBSD 0 + #define LIBFUZZER_FREEBSD 0 + #define LIBFUZZER_OPENBSD 1 #else -#error "Support for your platform has not been implemented" + #error "Support for your platform has not been implemented" #endif -int __afl_sharedmem_fuzzing = 1; -extern unsigned int *__afl_fuzz_len; +int __afl_sharedmem_fuzzing = 1; +extern unsigned int * __afl_fuzz_len; extern unsigned char *__afl_fuzz_ptr; // libFuzzer interface is thin, so we don't include any libFuzzer headers. @@ -105,11 +108,11 @@ __attribute__((weak)) int LLVMFuzzerInitialize(int *argc, char ***argv); // Notify AFL about persistent mode. static volatile char AFL_PERSISTENT[] = "##SIG_AFL_PERSISTENT##"; -int __afl_persistent_loop(unsigned int); +int __afl_persistent_loop(unsigned int); // Notify AFL about deferred forkserver. static volatile char AFL_DEFER_FORKSVR[] = "##SIG_AFL_DEFER_FORKSRV##"; -void __afl_manual_init(); +void __afl_manual_init(); // Use this optionally defined function to output sanitizer messages even if // user asks to close stderr. @@ -122,98 +125,121 @@ static FILE *output_file; // Experimental feature to use afl_driver without AFL's deferred mode. // Needs to run before __afl_auto_init. __attribute__((constructor(0))) static void __decide_deferred_forkserver(void) { + if (getenv("AFL_DRIVER_DONT_DEFER")) { + if (unsetenv("__AFL_DEFER_FORKSRV")) { + perror("Failed to unset __AFL_DEFER_FORKSRV"); abort(); + } + } + } // If the user asks us to duplicate stderr, then do it. static void maybe_duplicate_stderr() { + char *stderr_duplicate_filename = getenv("AFL_DRIVER_STDERR_DUPLICATE_FILENAME"); - if (!stderr_duplicate_filename) - return; + if (!stderr_duplicate_filename) return; FILE *stderr_duplicate_stream = freopen(stderr_duplicate_filename, "a+", stderr); if (!stderr_duplicate_stream) { + fprintf( stderr, "Failed to duplicate stderr to AFL_DRIVER_STDERR_DUPLICATE_FILENAME"); abort(); + } + output_file = stderr_duplicate_stream; + } // Most of these I/O functions were inspired by/copied from libFuzzer's code. static void discard_output(int fd) { + FILE *temp = fopen("/dev/null", "w"); - if (!temp) - abort(); + if (!temp) abort(); dup2(fileno(temp), fd); fclose(temp); + } -static void close_stdout() { discard_output(STDOUT_FILENO); } +static void close_stdout() { + + discard_output(STDOUT_FILENO); + +} // Prevent the targeted code from writing to "stderr" but allow sanitizers and // this driver to do so. static void dup_and_close_stderr() { + int output_fileno = fileno(output_file); int output_fd = dup(output_fileno); - if (output_fd <= 0) - abort(); + if (output_fd <= 0) abort(); FILE *new_output_file = fdopen(output_fd, "w"); - if (!new_output_file) - abort(); - if (!__sanitizer_set_report_fd) - return; - __sanitizer_set_report_fd((void*)output_fd); + if (!new_output_file) abort(); + if (!__sanitizer_set_report_fd) return; + __sanitizer_set_report_fd((void *)output_fd); discard_output(output_fileno); + } // Close stdout and/or stderr if user asks for it. static void maybe_close_fd_mask() { + char *fd_mask_str = getenv("AFL_DRIVER_CLOSE_FD_MASK"); - if (!fd_mask_str) - return; + if (!fd_mask_str) return; int fd_mask = atoi(fd_mask_str); - if (fd_mask & 2) - dup_and_close_stderr(); - if (fd_mask & 1) - close_stdout(); + if (fd_mask & 2) dup_and_close_stderr(); + if (fd_mask & 1) close_stdout(); + } // Define LLVMFuzzerMutate to avoid link failures for targets that use it // with libFuzzer's LLVMFuzzerCustomMutator. size_t LLVMFuzzerMutate(uint8_t *Data, size_t Size, size_t MaxSize) { - //assert(false && "LLVMFuzzerMutate should not be called from afl_driver"); + + // assert(false && "LLVMFuzzerMutate should not be called from afl_driver"); return 0; + } // Execute any files provided as parameters. static int ExecuteFilesOnyByOne(int argc, char **argv) { + unsigned char *buf = malloc(MAX_FILE); for (int i = 1; i < argc; i++) { + int fd = open(argv[i], O_RDONLY); if (fd == -1) continue; ssize_t length = read(fd, buf, MAX_FILE); if (length > 0) { + printf("Reading %zu bytes from %s\n", length, argv[i]); LLVMFuzzerTestOneInput(buf, length); printf("Execution successful.\n"); + } + } + free(buf); return 0; + } int main(int argc, char **argv) { + printf( "======================= INFO =========================\n" "This binary is built for AFL-fuzz.\n" @@ -226,36 +252,39 @@ int main(int argc, char **argv) { "afl-fuzz will run N iterations before " "re-spawning the process (default: 1000)\n" "======================================================\n", - argv[0], argv[0], argv[0]); + argv[0], argv[0], argv[0]); output_file = stderr; maybe_duplicate_stderr(); maybe_close_fd_mask(); - if (LLVMFuzzerInitialize) - LLVMFuzzerInitialize(&argc, &argv); + if (LLVMFuzzerInitialize) LLVMFuzzerInitialize(&argc, &argv); // Do any other expensive one-time initialization here. uint8_t dummy_input[64] = {0}; - memcpy(dummy_input, (void*)AFL_PERSISTENT, sizeof(AFL_PERSISTENT)); - memcpy(dummy_input + 32, (void*)AFL_DEFER_FORKSVR, sizeof(AFL_DEFER_FORKSVR)); + memcpy(dummy_input, (void *)AFL_PERSISTENT, sizeof(AFL_PERSISTENT)); + memcpy(dummy_input + 32, (void *)AFL_DEFER_FORKSVR, + sizeof(AFL_DEFER_FORKSVR)); int N = INT_MAX; if (argc == 2 && argv[1][0] == '-') - N = atoi(argv[1] + 1); - else if(argc == 2 && (N = atoi(argv[1])) > 0) - printf("WARNING: using the deprecated call style `%s %d`\n", argv[0], N); + N = atoi(argv[1] + 1); + 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")) { - __afl_sharedmem_fuzzing = 0; - __afl_manual_init(); -// } + + // 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")) + // if (!getenv("AFL_DRIVER_DONT_DEFER")) __afl_manual_init(); // Call LLVMFuzzerTestOneInput here so that coverage caused by initialization @@ -264,17 +293,26 @@ int main(int argc, char **argv) { int num_runs = 0; while (__afl_persistent_loop(N)) { + #ifdef _DEBUG - fprintf(stderr, "CLIENT crc: %016llx len: %u\n", hash64(__afl_fuzz_ptr, *__afl_fuzz_len, 0xa5b35705), *__afl_fuzz_len); + fprintf(stderr, "CLIENT crc: %016llx len: %u\n", + hash64(__afl_fuzz_ptr, *__afl_fuzz_len, 0xa5b35705), + *__afl_fuzz_len); fprintf(stderr, "RECV:"); for (int i = 0; i < *__afl_fuzz_len; i++) fprintf(stderr, "%02x", __afl_fuzz_ptr[i]); - fprintf(stderr,"\n"); + fprintf(stderr, "\n"); #endif if (*__afl_fuzz_len) { + num_runs++; LLVMFuzzerTestOneInput(__afl_fuzz_ptr, *__afl_fuzz_len); + } + } + printf("%s: successfully executed %d input(s)\n", argv[0], num_runs); + } + diff --git a/examples/aflpp_driver/aflpp_driver_test.c b/examples/aflpp_driver/aflpp_driver_test.c index 83278f5c..e4567bbf 100644 --- a/examples/aflpp_driver/aflpp_driver_test.c +++ b/examples/aflpp_driver/aflpp_driver_test.c @@ -6,18 +6,20 @@ int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { - fprintf(stderr, "FUNC crc: %016llx len: %lu\n", hash64((u8*)Data, (unsigned int) Size, (unsigned long long int) 0xa5b35705), Size); - - if (Size < 5) - return 0; + fprintf(stderr, "FUNC crc: %016llx len: %lu\n", + hash64((u8 *)Data, (unsigned int)Size, + (unsigned long long int)0xa5b35705), + Size); + + if (Size < 5) return 0; if (Data[0] == 'F') if (Data[1] == 'A') if (Data[2] == '$') if (Data[3] == '$') - if (Data[4] == '$') - abort(); - + if (Data[4] == '$') abort(); + return 0; } + |