diff options
Diffstat (limited to 'src/afl-analyze.c')
| -rw-r--r-- | src/afl-analyze.c | 218 |
1 files changed, 81 insertions, 137 deletions
diff --git a/src/afl-analyze.c b/src/afl-analyze.c index aabdbf1a..606254d9 100644 --- a/src/afl-analyze.c +++ b/src/afl-analyze.c @@ -55,12 +55,7 @@ #include <sys/types.h> #include <sys/resource.h> -static s32 child_pid; /* PID of the tested program */ - -static u8 *trace_bits; /* SHM with instrumentation bitmap */ - -static u8 *in_file, /* Analyzer input test case */ - *prog_in; /* Targeted program input file */ +static u8 *in_file; /* Analyzer input test case */ static u8 *in_data; /* Input data for analysis */ @@ -73,20 +68,19 @@ static u64 orig_cksum; /* Original checksum */ static u64 mem_limit = MEM_LIMIT; /* Memory limit (MB) */ -static s32 dev_null_fd = -1; /* FD to /dev/null */ - static bool edges_only, /* Ignore hit counts? */ use_hex_offsets, /* Show hex offsets? */ use_stdin = true; /* Use stdin for program input? */ -static volatile u8 stop_soon, /* Ctrl-C pressed? */ - child_timed_out; /* Child timed out? */ +static volatile u8 stop_soon; /* Ctrl-C pressed? */ static u8 *target_path; static u8 frida_mode; static u8 qemu_mode; static u32 map_size = MAP_SIZE; +static afl_forkserver_t fsrv = {0}; /* The forkserver */ + /* Constants used for describing byte behavior. */ #define RESP_NONE 0x00 /* Changing byte is a no-op. */ @@ -156,7 +150,7 @@ static void classify_counts(u8 *mem) { static inline u8 anything_set(void) { - u32 *ptr = (u32 *)trace_bits; + u32 *ptr = (u32 *)fsrv.trace_bits; u32 i = (map_size >> 2); while (i--) { @@ -173,7 +167,7 @@ static inline u8 anything_set(void) { static void at_exit_handler(void) { - unlink(prog_in); /* Ignore errors */ + unlink(fsrv.out_file); /* Ignore errors */ } @@ -205,116 +199,29 @@ static void read_initial_file(void) { } -/* Write output file. */ - -static s32 write_to_file(u8 *path, u8 *mem, u32 len) { - - s32 ret; - - unlink(path); /* Ignore errors */ - - ret = open(path, O_RDWR | O_CREAT | O_EXCL, DEFAULT_PERMISSION); - - if (ret < 0) { PFATAL("Unable to create '%s'", path); } - - ck_write(ret, mem, len, path); - - lseek(ret, 0, SEEK_SET); - - return ret; - -} - /* Execute target application. Returns exec checksum, or 0 if program times out. */ -static u32 analyze_run_target(char **argv, u8 *mem, u32 len, u8 first_run) { - - static struct itimerval it; - int status = 0; - - s32 prog_in_fd; - u64 cksum; - - memset(trace_bits, 0, map_size); - MEM_BARRIER(); - - prog_in_fd = write_to_file(prog_in, mem, len); - - child_pid = fork(); - - if (child_pid < 0) { PFATAL("fork() failed"); } - - if (!child_pid) { - - struct rlimit r; - - if (dup2(use_stdin ? prog_in_fd : dev_null_fd, 0) < 0 || - dup2(dev_null_fd, 1) < 0 || dup2(dev_null_fd, 2) < 0) { - - *(u32 *)trace_bits = EXEC_FAIL_SIG; - PFATAL("dup2() failed"); - - } - - close(dev_null_fd); - close(prog_in_fd); - - if (mem_limit) { - - r.rlim_max = r.rlim_cur = ((rlim_t)mem_limit) << 20; - -#ifdef RLIMIT_AS - - setrlimit(RLIMIT_AS, &r); /* Ignore errors */ +static u32 analyze_run_target(u8 *mem, u32 len, u8 first_run) { -#else - - setrlimit(RLIMIT_DATA, &r); /* Ignore errors */ - -#endif /* ^RLIMIT_AS */ - - } - - r.rlim_max = r.rlim_cur = 0; - setrlimit(RLIMIT_CORE, &r); /* Ignore errors */ - - execv(target_path, argv); - - *(u32 *)trace_bits = EXEC_FAIL_SIG; - exit(0); + afl_fsrv_write_to_testcase(&fsrv, mem, len); + fsrv_run_result_t ret = afl_fsrv_run_target(&fsrv, exec_tmout, &stop_soon); - } - - close(prog_in_fd); - - /* Configure timeout, wait for child, cancel timeout. */ - - child_timed_out = 0; - it.it_value.tv_sec = (exec_tmout / 1000); - it.it_value.tv_usec = (exec_tmout % 1000) * 1000; + if (ret == FSRV_RUN_ERROR) { - setitimer(ITIMER_REAL, &it, NULL); + FATAL("Error in forkserver"); - if (waitpid(child_pid, &status, 0) <= 0) { FATAL("waitpid() failed"); } + } else if (ret == FSRV_RUN_NOINST) { - child_pid = 0; - it.it_value.tv_sec = 0; - it.it_value.tv_usec = 0; + FATAL("Target not instrumented"); - setitimer(ITIMER_REAL, &it, NULL); + } else if (ret == FSRV_RUN_NOBITS) { - MEM_BARRIER(); - - /* Clean up bitmap, analyze exit condition, etc. */ - - if (*(u32 *)trace_bits == EXEC_FAIL_SIG) { - - FATAL("Unable to execute '%s'", argv[0]); + FATAL("Failed to run target"); } - classify_counts(trace_bits); + classify_counts(fsrv.trace_bits); total_execs++; if (stop_soon) { @@ -326,21 +233,19 @@ static u32 analyze_run_target(char **argv, u8 *mem, u32 len, u8 first_run) { /* Always discard inputs that time out. */ - if (child_timed_out) { + if (fsrv.last_run_timed_out) { exec_hangs++; return 0; } - cksum = hash64(trace_bits, map_size, HASH_CONST); + u64 cksum = hash64(fsrv.trace_bits, fsrv.map_size, HASH_CONST); - /* We don't actually care if the target is crashing or not, - except that when it does, the checksum should be different. */ + if (ret == FSRV_RUN_CRASH) { - if (WIFSIGNALED(status) || - (WIFEXITED(status) && WEXITSTATUS(status) == MSAN_ERROR) || - (WIFEXITED(status) && WEXITSTATUS(status))) { + /* We don't actually care if the target is crashing or not, + except that when it does, the checksum should be different. */ cksum ^= 0xffffffff; @@ -604,7 +509,7 @@ static void dump_hex(u32 len, u8 *b_data) { /* Actually analyze! */ -static void analyze(char **argv) { +static void analyze() { u32 i; u32 boring_len = 0, prev_xff = 0, prev_x01 = 0, prev_s10 = 0, prev_a10 = 0; @@ -630,16 +535,16 @@ static void analyze(char **argv) { code. */ in_data[i] ^= 0xff; - xor_ff = analyze_run_target(argv, in_data, in_len, 0); + xor_ff = analyze_run_target(in_data, in_len, 0); in_data[i] ^= 0xfe; - xor_01 = analyze_run_target(argv, in_data, in_len, 0); + xor_01 = analyze_run_target(in_data, in_len, 0); in_data[i] = (in_data[i] ^ 0x01) - 0x10; - sub_10 = analyze_run_target(argv, in_data, in_len, 0); + sub_10 = analyze_run_target(in_data, in_len, 0); in_data[i] += 0x20; - add_10 = analyze_run_target(argv, in_data, in_len, 0); + add_10 = analyze_run_target(in_data, in_len, 0); in_data[i] -= 0x10; /* Classify current behavior. */ @@ -712,7 +617,7 @@ static void handle_stop_sig(int sig) { (void)sig; stop_soon = 1; - if (child_pid > 0) { kill(child_pid, SIGKILL); } + afl_fsrv_killall(); } @@ -724,10 +629,10 @@ static void set_up_environment(char **argv) { char *afl_preload; char *frida_afl_preload = NULL; - dev_null_fd = open("/dev/null", O_RDWR); - if (dev_null_fd < 0) { PFATAL("Unable to open /dev/null"); } + fsrv.dev_null_fd = open("/dev/null", O_RDWR); + if (fsrv.dev_null_fd < 0) { PFATAL("Unable to open /dev/null"); } - if (!prog_in) { + if (!fsrv.out_file) { u8 *use_dir = "."; @@ -738,10 +643,15 @@ static void set_up_environment(char **argv) { } - prog_in = alloc_printf("%s/.afl-analyze-temp-%u", use_dir, (u32)getpid()); + fsrv.out_file = alloc_printf("%s/.afl-analyze-temp-%u", use_dir, (u32)getpid()); } + unlink(fsrv.out_file); + fsrv.out_fd = open(fsrv.out_file, O_RDWR | O_CREAT | O_EXCL, DEFAULT_PERMISSION); + + if (fsrv.out_fd < 0) { PFATAL("Unable to create '%s'", fsrv.out_file); } + /* Set sane defaults... */ x = get_afl_env("ASAN_OPTIONS"); @@ -965,6 +875,8 @@ int main(int argc, char **argv_orig, char **envp) { SAYF(cCYA "afl-analyze" VERSION cRST " by Michal Zalewski\n"); + afl_fsrv_init(&fsrv); + while ((opt = getopt(argc, argv, "+i:f:m:t:eOQUWh")) > 0) { switch (opt) { @@ -977,9 +889,9 @@ int main(int argc, char **argv_orig, char **envp) { case 'f': - if (prog_in) { FATAL("Multiple -f options not supported"); } - use_stdin = 0; - prog_in = optarg; + if (fsrv.out_file) { FATAL("Multiple -f options not supported"); } + fsrv.use_stdin = 0; + fsrv.out_file = ck_strdup(optarg); break; case 'e': @@ -1000,6 +912,7 @@ int main(int argc, char **argv_orig, char **envp) { if (!strcmp(optarg, "none")) { mem_limit = 0; + fsrv.mem_limit = 0; break; } @@ -1038,6 +951,8 @@ int main(int argc, char **argv_orig, char **envp) { } + fsrv.mem_limit = mem_limit; + } break; @@ -1057,6 +972,8 @@ int main(int argc, char **argv_orig, char **envp) { } + fsrv.exec_tmout = exec_tmout; + break; case 'O': /* FRIDA mode */ @@ -1064,6 +981,7 @@ int main(int argc, char **argv_orig, char **envp) { if (frida_mode) { FATAL("Multiple -O options not supported"); } frida_mode = 1; + fsrv.frida_mode = frida_mode; break; @@ -1073,6 +991,8 @@ int main(int argc, char **argv_orig, char **envp) { if (!mem_limit_given) { mem_limit = MEM_LIMIT_QEMU; } qemu_mode = 1; + fsrv.mem_limit = mem_limit; + fsrv.qemu_mode = qemu_mode; break; case 'U': @@ -1081,6 +1001,7 @@ int main(int argc, char **argv_orig, char **envp) { if (!mem_limit_given) { mem_limit = MEM_LIMIT_UNICORN; } unicorn_mode = 1; + fsrv.mem_limit = mem_limit; break; case 'W': /* Wine+QEMU mode */ @@ -1090,6 +1011,8 @@ int main(int argc, char **argv_orig, char **envp) { use_wine = 1; if (!mem_limit_given) { mem_limit = 0; } + fsrv.qemu_mode = qemu_mode; + fsrv.mem_limit = mem_limit; break; @@ -1108,6 +1031,7 @@ int main(int argc, char **argv_orig, char **envp) { if (optind == argc || !in_file) { usage(argv[0]); } map_size = get_map_size(); + fsrv.map_size = map_size; use_hex_offsets = !!get_afl_env("AFL_ANALYZE_HEX"); @@ -1117,14 +1041,15 @@ int main(int argc, char **argv_orig, char **envp) { /* initialize cmplog_mode */ shm.cmplog_mode = 0; - trace_bits = afl_shm_init(&shm, map_size, 0); + atexit(at_exit_handler); setup_signal_handlers(); set_up_environment(argv); - target_path = find_binary(argv[optind]); - detect_file_args(argv + optind, prog_in, &use_stdin); + fsrv.target_path = find_binary(argv[optind]); + fsrv.trace_bits = afl_shm_init(&shm, map_size, 0); + detect_file_args(argv + optind, fsrv.out_file, &use_stdin); if (qemu_mode) { @@ -1148,14 +1073,31 @@ int main(int argc, char **argv_orig, char **envp) { SAYF("\n"); + if (getenv("AFL_FORKSRV_INIT_TMOUT")) { + + s32 forksrv_init_tmout = atoi(getenv("AFL_FORKSRV_INIT_TMOUT")); + if (forksrv_init_tmout < 1) { + + FATAL("Bad value specified for AFL_FORKSRV_INIT_TMOUT"); + + } + + fsrv.init_tmout = (u32)forksrv_init_tmout; + + } + + fsrv.kill_signal = + parse_afl_kill_signal_env(getenv("AFL_KILL_SIGNAL"), SIGKILL); + read_initial_file(); ACTF("Performing dry run (mem limit = %llu MB, timeout = %u ms%s)...", mem_limit, exec_tmout, edges_only ? ", edges only" : ""); - analyze_run_target(use_argv, in_data, in_len, 1); + afl_fsrv_start(&fsrv, use_argv, &stop_soon, false); + analyze_run_target(in_data, in_len, 1); - if (child_timed_out) { + if (fsrv.last_run_timed_out) { FATAL("Target binary times out (adjusting -t may help)."); @@ -1167,13 +1109,15 @@ int main(int argc, char **argv_orig, char **envp) { } - analyze(use_argv); + analyze(); OKF("We're done here. Have a nice day!\n"); - if (target_path) { ck_free(target_path); } - afl_shm_deinit(&shm); + afl_fsrv_deinit(&fsrv); + if (fsrv.target_path) { ck_free(fsrv.target_path); } + if (in_data) { ck_free(in_data); } + exit(0); |