Mutator: fix mutator crash due to output truncated by harness

atrosinenko · Jan 6, 2024 · 58ab681 · 58ab681
1 parent 1a62750
commit 58ab681
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Showing 3 changed files with 6 additions and 2 deletions.
diff --git a/runtime/common/input.c b/runtime/common/input.c
@@ -25,6 +25,8 @@ void res_load_whole_stdin(struct fuzzer_state *state) {
     perror("Cannot read input from stdin");
     abort();
   }
+
+  assert(MAX_INPUT_LEN == MUTATOR_MAX_TEST_CASE_LENGTH); // statically known
   TRACE(state, "Read %zu bytes of input (max %u).", state->constant_state.length, MAX_INPUT_LEN);
   mutator_init_input(state);
   for (int id = 0; id < state->current_state.file_name_count; ++id)

diff --git a/runtime/include/kbdysch/mutator-defs.h b/runtime/include/kbdysch/mutator-defs.h
@@ -112,7 +112,8 @@ struct mutator_log_propose_change {
 };
 #pragma pack(pop)
 
-#define MUTATOR_MAX_TEST_CASE_LENGTH (1 << 20)
+// Should be equal to MAX_INPUT_LEN
+#define MUTATOR_MAX_TEST_CASE_LENGTH (1 << 16)
 
 #define MUTATOR_MAX_VARIABLES 100
 #define MUTATOR_SHM_VARS_BYTES 65536

diff --git a/runtime/mutators/afl-generic-mutator.cpp b/runtime/mutators/afl-generic-mutator.cpp
@@ -301,7 +301,8 @@ uint8_t afl_custom_queue_new_entry(void *data, const char *filename_new_queue,
 
   bool log_saved = save_log_from_shm(state, test_case.as_data(), filename_new_queue);
   if (!log_saved && !strstr(filename_new_queue, ",orig:"))
-    FATAL("Unexpected hash: %s\n", filename_new_queue);
+    FATAL("Unexpected hash: length=%zu, filename=%s\n",
+          test_case.size(), filename_new_queue);
   // Do not initialize too early
   if (log_saved)
     accumulate_important_data(state);