tests: internal: fuzzers: add config yaml fuzzer

CMakeLists.txt

@@ -369,8 +369,6 @@ endif()
 
 if (FLB_TESTS_OSSFUZZ)
   FLB_DEFINITION(FLB_HAVE_TESTS_OSSFUZZ)
-  # Disable for fuzz testing
-  set(FLB_CONFIG_YAML Off)
 endif()
 
 if (FLB_WASM)

tests/internal/fuzzers/CMakeLists.txt

@@ -24,6 +24,7 @@ set(UNIT_TESTS_FILES
   utils_fuzzer.c
   config_map_fuzzer.c
   record_ac_fuzzer.c
+  config_yaml_fuzzer.c
   )
 
 # Prepare list of unit tests

tests/internal/fuzzers/config_yaml_fuzzer.c

@@ -0,0 +1,65 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  Fluent Bit
+ *  ==========
+ *  Copyright (C) 2015-2023 The Fluent Bit Authors
+ *
+ *  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
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <fluent-bit/flb_info.h>
+#include <fluent-bit/flb_mem.h>
+#include <fluent-bit/flb_kv.h>
+#include <fluent-bit/flb_config_format.h>
+
+#include <cfl/cfl.h>
+#include <cfl/cfl_list.h>
+
+#include "flb_fuzz_header.h"
+
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
+{
+    /* Set fuzzer-malloc chance of failure */
+    flb_malloc_p = 0;
+    flb_malloc_mod = 25000;
+
+    /* Limit the size of the config files to 32KB. */
+    if (size > 32768) {
+        return 0;
+    }
+
+    /* Write the config file to a location we know OSS-Fuzz has */
+    char filename[256];
+    sprintf(filename, "/tmp/libfuzzer.%d.yaml", getpid());
+    FILE *fp = fopen(filename, "wb");
+    if (!fp) {
+        return 0;
+    }
+    fwrite(data, size, 1, fp);
+    fclose(fp);
+
+
+    struct flb_cf *cf;
+    struct flb_cf_section *s;
+
+    cf = flb_cf_yaml_create(NULL, filename, NULL, 0);
+    if (cf != NULL) {
+        flb_cf_destroy(cf);
+    }
+
+    /* clean up the file */
+    unlink(filename);
+
+    return 0;
+}