Merge pull request #2128 from AFLplusplus/fastrestart

Fastrestart

docs/env_variables.md

@@ -514,6 +514,8 @@ checks or alter some of the more exotic semantics of the tool:
   - `AFL_NO_SNAPSHOT` will advise afl-fuzz not to use the snapshot feature if
     the snapshot lkm is loaded.
 
+  - `AFL_NO_FASTRESUME` will not try to read or write a fast resume file.
+
   - Setting `AFL_NO_UI` inhibits the UI altogether and just periodically prints
     some basic stats. This behavior is also automatically triggered when the
     output from afl-fuzz is redirected to a file or to a pipe.

include/afl-fuzz.h

@@ -236,7 +236,6 @@ struct queue_entry {
       custom,                           /* Marker for custom mutators       */
       stats_mutated;                    /* stats: # of mutations performed  */
 
-  u8 *trace_mini;                       /* Trace bytes, if kept             */
   u32 tc_ref;                           /* Trace bytes ref count            */
 
 #ifdef INTROSPECTION
@@ -246,13 +245,11 @@ struct queue_entry {
   double perf_score,                    /* performance score                */
       weight;
 
+  struct queue_entry *mother;            /* queue entry this based on        */
+  u8                 *trace_mini;        /* Trace bytes, if kept             */
   u8                 *testcase_buf;      /* The testcase buffer, if loaded.  */
-
   u8                 *cmplog_colorinput; /* the result buf of colorization   */
   struct tainted     *taint;             /* Taint information from CmpLog    */
-
-  struct queue_entry *mother;           /* queue entry this based on        */
-
   struct skipdet_entry *skipdet_e;
 
 };
@@ -457,7 +454,7 @@ typedef struct afl_env_vars {
       afl_no_startup_calibration, afl_no_warn_instability,
       afl_post_process_keep_original, afl_crashing_seeds_as_new_crash,
       afl_final_sync, afl_ignore_seed_problems, afl_disable_redundant,
-      afl_sha1_filenames, afl_no_sync;
+      afl_sha1_filenames, afl_no_sync, afl_no_fastresume;
 
   u8 *afl_tmpdir, *afl_custom_mutator_library, *afl_python_module, *afl_path,
       *afl_hang_tmout, *afl_forksrv_init_tmout, *afl_preload,

include/envs.h

@@ -115,7 +115,7 @@ static char *afl_environment_variables[] = {
     "AFL_TRACE_PC", "AFL_USE_ASAN", "AFL_USE_MSAN", "AFL_USE_TRACE_PC",
     "AFL_USE_UBSAN", "AFL_USE_TSAN", "AFL_USE_CFISAN", "AFL_USE_LSAN",
     "AFL_WINE_PATH", "AFL_NO_SNAPSHOT", "AFL_EXPAND_HAVOC_NOW", "AFL_USE_FASAN",
-    "AFL_USE_QASAN", "AFL_PRINT_FILENAMES", "AFL_PIZZA_MODE", NULL
+    "AFL_USE_QASAN", "AFL_PRINT_FILENAMES", "AFL_PIZZA_MODE", "AFL_NO_FASTRESUME", NULL
 
 };
 

src/afl-fuzz-init.c

@@ -1019,7 +1019,7 @@ void perform_dry_run(afl_state_t *afl) {
 
           }
 
-          if (!q->was_fuzzed) {
+          if (unlikely(!q->was_fuzzed)) {
 
             q->was_fuzzed = 1;
             afl->reinit_table = 1;

src/afl-fuzz-queue.c

@@ -401,7 +401,7 @@ void mark_as_redundant(afl_state_t *afl, struct queue_entry *q, u8 state) {
 
   } else {
 
-    if (unlink(fn)) { PFATAL("Unable to remove '%s'", fn); }
+    if (unlink(fn)) { /*PFATAL("Unable to remove '%s'", fn);*/ }
 
   }
 
@@ -700,11 +700,10 @@ void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) {
 void destroy_queue(afl_state_t *afl) {
 
   u32                 i;
+  struct queue_entry *q;
 
   for (i = 0; i < afl->queued_items; i++) {
 
-    struct queue_entry *q;
-
     q = afl->queue_buf[i];
     ck_free(q->fname);
     ck_free(q->trace_mini);

src/afl-fuzz-state.c

@@ -286,6 +286,13 @@ void read_afl_environment(afl_state_t *afl, char **envp) {
             afl->afl_env.afl_no_sync =
                 get_afl_env(afl_environment_variables[i]) ? 1 : 0;
 
+          } else if (!strncmp(env, "AFL_NO_FASTRESUME",
+
+                              afl_environment_variable_len)) {
+
+            afl->afl_env.afl_no_fastresume =
+                get_afl_env(afl_environment_variables[i]) ? 1 : 0;
+
           } else if (!strncmp(env, "AFL_CUSTOM_MUTATOR_ONLY",
 
                               afl_environment_variable_len)) {

src/afl-fuzz-stats.c

@@ -76,7 +76,13 @@ char *get_fuzzing_state(afl_state_t *afl) {
 
 void write_setup_file(afl_state_t *afl, u32 argc, char **argv) {
 
-  u8 fn[PATH_MAX];
+  u8 fn[PATH_MAX], fn2[PATH_MAX];
+
+  snprintf(fn2, PATH_MAX, "%s/target_hash", afl->out_dir);
+  FILE *f2 = create_ffile(fn2);
+  fprintf(f2, "%p\n", (void *)get_binary_hash(afl->fsrv.target_path));
+  fclose(f2);
+
   snprintf(fn, PATH_MAX, "%s/fuzzer_setup", afl->out_dir);
   FILE *f = create_ffile(fn);
   u32   i;

src/afl-fuzz.c

@@ -181,7 +181,7 @@ static void usage(u8 *argv0, int more_help) {
       "it.\n"
       "                  if using QEMU/FRIDA or the fuzzing target is "
       "compiled\n"
-      "                  for CmpLog then use '-c 0'. To disable Cmplog use '-c "
+      "                  for CmpLog then use '-c 0'. To disable CMPLOG use '-c "
       "-'.\n"
       "  -l cmplog_opts - CmpLog configuration values (e.g. \"2ATR\"):\n"
       "                  1=small files, 2=larger files (default), 3=all "
@@ -335,6 +335,7 @@ static void usage(u8 *argv0, int more_help) {
       "AFL_STATSD_PORT: change default statsd port (default: 8125)\n"
       "AFL_STATSD_TAGS_FLAVOR: set statsd tags format (default: disable tags)\n"
       "                        suported formats: dogstatsd, librato, signalfx, influxdb\n"
+      "AFL_NO_FASTRESUME: do not read or write a fast resume file\n"
       "AFL_NO_SYNC: disables all syncing\n"
       "AFL_SYNC_TIME: sync time between fuzzing instances (in minutes)\n"
       "AFL_FINAL_SYNC: sync a final time when exiting (will delay the exit!)\n"
@@ -2105,13 +2106,80 @@ int main(int argc, char **argv_orig, char **envp) {
 
   }
 
+  setup_cmdline_file(afl, argv + optind);
+  check_binary(afl, argv[optind]);
+
+  u64 prev_target_hash = 0;
+  s32 fast_resume = 0, fr_fd = -1;
+
+  if (afl->in_place_resume && !afl->afl_env.afl_no_fastresume) {
+
+    u8 fn[PATH_MAX], buf[32];
+    snprintf(fn, PATH_MAX, "%s/target_hash", afl->out_dir);
+    fr_fd = open(fn, O_RDONLY);
+    if (fr_fd >= 0) {
+
+      if (read(fr_fd, buf, 32) >= 16) {
+
+        sscanf(buf, "%p", (void **)&prev_target_hash);
+
+      }
+
+      close(fr_fd);
+
+    }
+
+  }
+
   write_setup_file(afl, argc, argv);
 
-  setup_cmdline_file(afl, argv + optind);
+  if (afl->in_place_resume && !afl->afl_env.afl_no_fastresume) {
+
+    u64 target_hash = get_binary_hash(afl->fsrv.target_path);
+
+    if (!target_hash || prev_target_hash != target_hash) {
+
+      ACTF("Target binary is different, cannot perform FAST RESUME!");
+
+    } else {
+
+      u8 fn[PATH_MAX];
+      snprintf(fn, PATH_MAX, "%s/fastresume.bin", afl->out_dir);
+      if ((fr_fd = open(fn, O_RDONLY)) >= 0) {
+
+        u8   ver_string[8];
+        u64 *ver = (u64 *)ver_string;
+        u64  expect_ver =
+            afl->shm.cmplog_mode + (sizeof(struct queue_entry) << 1);
+
+        if (read(fr_fd, ver_string, sizeof(ver_string)) != sizeof(ver_string))
+          WARNF("Emtpy fastresume.bin, ignoring, cannot perform FAST RESUME");
+        else if (expect_ver != *ver)
+          WARNF(
+              "Different AFL++ version or feature usage, cannot perform FAST "
+              "RESUME");
+        else {
+
+          OKF("Will perform FAST RESUME");
+          fast_resume = 1;
+
+        }
+
+      } else {
+
+        ACTF("fastresume.bin not found, cannot perform FAST RESUME!");
+
+      }
+
+      // If the fast resume file is not valid we will be unable to start, so
+      // we remove the file but keep the file descriptor open.
+      unlink(fn);
+
+    }
+
+  }
 
   read_testcases(afl, NULL);
-  // read_foreign_testcases(afl, 1); for the moment dont do this
-  OKF("Loaded a total of %u seeds.", afl->queued_items);
 
   pivot_inputs(afl);
 
@@ -2144,6 +2212,9 @@ int main(int argc, char **argv_orig, char **envp) {
 
   }
 
+  // read_foreign_testcases(afl, 1); for the moment dont do this
+  OKF("Loaded a total of %u seeds.", afl->queued_items);
+
   /* If we don't have a file name chosen yet, use a safe default. */
 
   if (!afl->fsrv.out_file) {
@@ -2200,8 +2271,6 @@ int main(int argc, char **argv_orig, char **envp) {
 
   }
 
-  check_binary(afl, argv[optind]);
-
   #ifdef AFL_PERSISTENT_RECORD
   if (unlikely(afl->fsrv.persistent_record)) {
 
@@ -2420,7 +2489,7 @@ int main(int argc, char **argv_orig, char **envp) {
 
     }
 
-    OKF("Cmplog forkserver successfully started");
+    OKF("CMPLOG forkserver successfully started");
 
   }
 
@@ -2458,6 +2527,77 @@ int main(int argc, char **argv_orig, char **envp) {
   dedup_extras(afl);
   if (afl->extras_cnt) { OKF("Loaded a total of %u extras.", afl->extras_cnt); }
 
+  if (unlikely(fast_resume)) {
+
+    u64 resume_start = get_cur_time_us();
+    // if we get here then we should abort on errors
+    ck_read(fr_fd, afl->virgin_bits, afl->fsrv.map_size, "virgin_bits");
+    ck_read(fr_fd, afl->virgin_tmout, afl->fsrv.map_size, "virgin_tmout");
+    ck_read(fr_fd, afl->virgin_crash, afl->fsrv.map_size, "virgin_crash");
+    ck_read(fr_fd, afl->var_bytes, afl->fsrv.map_size, "var_bytes");
+
+    u8                  res[1] = {0};
+    u8                 *o_start = (u8 *)&(afl->queue_buf[0]->colorized);
+    u8                 *o_end = (u8 *)&(afl->queue_buf[0]->mother);
+    u32                 r = 8 + afl->fsrv.map_size * 4;
+    u32                 q_len = o_end - o_start;
+    u32                 m_len = (afl->fsrv.map_size >> 3);
+    struct queue_entry *q;
+
+    for (u32 i = 0; i < afl->queued_items; i++) {
+
+      q = afl->queue_buf[i];
+      ck_read(fr_fd, (u8 *)&(q->colorized), q_len, "queue data");
+      ck_read(fr_fd, res, 1, "check map");
+      if (res[0]) {
+
+        q->trace_mini = ck_alloc(m_len);
+        ck_read(fr_fd, q->trace_mini, m_len, "trace_mini");
+        r += q_len + m_len + 1;
+
+      } else {
+
+        r += q_len + 1;
+
+      }
+
+      afl->total_bitmap_size += q->bitmap_size;
+      ++afl->total_bitmap_entries;
+      update_bitmap_score(afl, q);
+
+      if (q->was_fuzzed) { --afl->pending_not_fuzzed; }
+
+      if (q->disabled) {
+
+        if (!q->was_fuzzed) { --afl->pending_not_fuzzed; }
+        --afl->active_items;
+
+      }
+
+      if (q->var_behavior) { ++afl->queued_variable; }
+      if (q->favored) {
+
+        ++afl->queued_favored;
+        if (!q->was_fuzzed) { ++afl->pending_favored; }
+
+      }
+
+    }
+
+    u8 buf[4];
+    if (read(fr_fd, buf, 3) > 0) {
+
+      FATAL("invalid trailing data in fastresume.bin");
+
+    }
+
+    OKF("Successfully loaded fastresume.bin (%u bytes)!", r);
+    close(fr_fd);
+    afl->reinit_table = 1;
+    update_calibration_time(afl, &resume_start);
+
+  } else {
+
     // after we have the correct bitmap size we can read the bitmap -B option
     // and set the virgin maps
     if (afl->in_bitmap) {
@@ -2479,11 +2619,13 @@ int main(int argc, char **argv_orig, char **envp) {
 
     } else {
 
-    ACTF("skipping initial seed calibration due option override!");
+      ACTF("Skipping initial seed calibration due option override!");
       usleep(1000);
 
     }
 
+  }
+
   if (afl->q_testcase_max_cache_entries) {
 
     afl->q_testcase_cache =
@@ -3071,6 +3213,66 @@ stop_fuzzing:
   fclose(afl->fsrv.det_plot_file);
   #endif
 
+  if (!afl->afl_env.afl_no_fastresume) {
+  /* create fastresume.bin */
+  u8 fr[PATH_MAX];
+  snprintf(fr, PATH_MAX, "%s/fastresume.bin", afl->out_dir);
+  ACTF("Writing %s ...", fr);
+  if ((fr_fd = open(fr, O_WRONLY | O_TRUNC | O_CREAT, DEFAULT_PERMISSION)) >=
+      0) {
+
+    u8   ver_string[8];
+    u32  w = 0;
+    u64 *ver = (u64 *)ver_string;
+    *ver = afl->shm.cmplog_mode + (sizeof(struct queue_entry) << 1);
+
+    w += write(fr_fd, ver_string, sizeof(ver_string));
+
+    w += write(fr_fd, afl->virgin_bits, afl->fsrv.map_size);
+    w += write(fr_fd, afl->virgin_tmout, afl->fsrv.map_size);
+    w += write(fr_fd, afl->virgin_crash, afl->fsrv.map_size);
+    w += write(fr_fd, afl->var_bytes, afl->fsrv.map_size);
+
+    u8                  on[1] = {1}, off[1] = {0};
+    u8                 *o_start = (u8 *)&(afl->queue_buf[0]->colorized);
+    u8                 *o_end = (u8 *)&(afl->queue_buf[0]->mother);
+    u32                 q_len = o_end - o_start;
+    u32                 m_len = (afl->fsrv.map_size >> 3);
+    struct queue_entry *q;
+
+    afl->pending_not_fuzzed = afl->queued_items;
+    afl->active_items = afl->queued_items;
+
+    for (u32 i = 0; i < afl->queued_items; i++) {
+
+      q = afl->queue_buf[i];
+      ck_write(fr_fd, (u8 *)&(q->colorized), q_len, "queue data");
+      if (!q->trace_mini) {
+
+        ck_write(fr_fd, off, 1, "no_mini");
+        w += q_len + 1;
+
+      } else {
+
+        ck_write(fr_fd, on, 1, "yes_mini");
+        ck_write(fr_fd, q->trace_mini, m_len, "trace_mini");
+        w += q_len + m_len + 1;
+
+      }
+
+    }
+
+    close(fr_fd);
+    afl->var_byte_count = count_bytes(afl, afl->var_bytes);
+    OKF("Written fastresume.bin with %u bytes!", w);
+
+  } else {
+
+    WARNF("Could not create fastresume.bin");
+
+  }
+  }
+
   destroy_queue(afl);
   destroy_extras(afl);
   destroy_custom_mutators(afl);

src/afl-performance.c

@@ -99,11 +99,13 @@ inline u64 hash64(u8 *key, u32 len, u64 seed) {
 
 u64 get_binary_hash(u8 *fn) {
 
+  if (!fn) { return 0; }
   int fd = open(fn, O_RDONLY);
   if (fd < 0) { PFATAL("Unable to open '%s'", fn); }
   struct stat st;
   if (fstat(fd, &st) < 0) { PFATAL("Unable to fstat '%s'", fn); }
   u32 f_len = st.st_size;
+  if (!f_len) { return 0; }
   u8 *f_data = mmap(0, f_len, PROT_READ, MAP_PRIVATE, fd, 0);
   if (f_data == MAP_FAILED) { PFATAL("Unable to mmap file '%s'", fn); }
   close(fd);