OSS-Fuzz: Add new fuzzer targets scene loading

oss-fuzzers/fuzz_scene_loader.c

@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <string.h>
+#include <gpac/setup.h>
+#include <gpac/tools.h>
+#include <gpac/scenegraph.h>
+#include <gpac/scene_manager.h>
+#include <gpac/constants.h>
+
+int LLVMFuzzerInitialize(int *argc, char ***argv) {
+    gf_sys_init(GF_MemTrackerNone, NULL);
+    gf_log_set_tool_level(GF_LOG_ALL, GF_LOG_QUIET);
+    return 0;
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    if (size < 8 || size > 1 << 20) return 0;
+
+    uint8_t sel = data[0];
+    const uint8_t *payload = data + 1;
+    size_t payload_size = size - 1;
+
+    GF_SceneManager_LoadType type;
+    const char *ext;
+    switch (sel % 5) {
+    case 0: type = GF_SM_LOAD_BT;   ext = "bt";   break;
+    case 1: type = GF_SM_LOAD_VRML; ext = "wrl";  break;
+    case 2: type = GF_SM_LOAD_X3DV; ext = "x3dv"; break;
+    case 3: type = GF_SM_LOAD_XMTA; ext = "xmt";  break;
+    default:type = GF_SM_LOAD_X3D;  ext = "x3d";  break;
+    }
+
+    char filename[256];
+    snprintf(filename, sizeof(filename), "/tmp/libfuzzer.%d.%s", getpid(), ext);
+
+    FILE *fp = fopen(filename, "wb");
+    if (!fp) return 0;
+    if (payload_size) fwrite(payload, payload_size, 1, fp);
+    fclose(fp);
+
+    GF_SceneGraph *sg = gf_sg_new();
+    if (!sg) {
+        unlink(filename);
+        return 0;
+    }
+    GF_SceneManager *ctx = gf_sm_new(sg);
+    if (!ctx) {
+        gf_sg_del(sg);
+        unlink(filename);
+        return 0;
+    }
+
+    GF_SceneLoader load;
+    memset(&load, 0, sizeof(GF_SceneLoader));
+    load.fileName = filename;
+    load.ctx = ctx;
+    load.type = type;
+
+    GF_Err e = gf_sm_load_init(&load);
+    if (!e) gf_sm_load_run(&load);
+    gf_sm_load_done(&load);
+
+    gf_sm_del(ctx);
+    gf_sg_del(sg);
+
+    unlink(filename);
+    return 0;
+}