mtmd: add more sanity checks (#21047)

tools/mtmd/mtmd-helper.cpp

@@ -127,6 +127,7 @@ struct decode_embd_batch {
     std::vector<int8_t>         logits;
     llama_batch batch;
     decode_embd_batch(float * embd, int32_t n_tokens, int n_pos_per_embd, int n_mmproj_embd) : n_pos_per_embd(n_pos_per_embd), n_mmproj_embd(n_mmproj_embd) {
+        GGML_ASSERT(n_tokens > 0 && n_pos_per_embd > 0 && n_mmproj_embd > 0);
         pos     .resize(n_tokens * n_pos_per_embd);
         n_seq_id.resize(n_tokens);
         seq_ids .resize(n_tokens + 1);
@@ -157,6 +158,7 @@ struct decode_embd_batch {
     // M-RoPE for image
     void set_position_mrope_2d(llama_pos pos_0, int nx, int ny, llama_seq_id seq_id) {
         GGML_ASSERT(n_pos_per_embd == 4);
+        GGML_ASSERT(nx > 0 && ny > 0 && nx * ny == batch.n_tokens);
         seq_id_0[0] = seq_id;
         for (int y = 0; y < ny; y++) {
             for (int x = 0; x < nx; x++) {
@@ -192,6 +194,7 @@ struct decode_embd_batch {
     }
 
     llama_batch get_view(int offset, int n_tokens) {
+        GGML_ASSERT(offset >= 0 && n_tokens > 0 && offset + n_tokens <= batch.n_tokens);
         llama_pos * pos_ptr;
         pos_view.clear();
         pos_view.reserve(n_tokens * n_pos_per_embd);
@@ -235,6 +238,7 @@ int32_t mtmd_helper_decode_image_chunk(
         llama_seq_id seq_id,
         int32_t n_batch,
         llama_pos * new_n_past) {
+    GGML_ASSERT(n_batch > 0);
     auto chunk_type = mtmd_input_chunk_get_type(chunk);
     const char * name = chunk_type == MTMD_INPUT_CHUNK_TYPE_IMAGE ? "image" : "audio";
     if (chunk_type == MTMD_INPUT_CHUNK_TYPE_TEXT) {
@@ -312,6 +316,7 @@ int32_t mtmd_helper_eval_chunk_single(mtmd_context * ctx,
         int32_t n_batch,
         bool logits_last,
         llama_pos * new_n_past) {
+    GGML_ASSERT(n_batch > 0);
     int32_t ret;
     llama_batch text_batch = llama_batch_init(n_batch, 0, 1);
     auto chunk_type = mtmd_input_chunk_get_type(chunk);
@@ -508,6 +513,11 @@ mtmd_bitmap * mtmd_helper_bitmap_init_from_file(mtmd_context * ctx, const char *
     fseek(f, 0, SEEK_END);
     long file_size = ftell(f);
     fseek(f, 0, SEEK_SET);
+    if (file_size < 0) {
+        LOG_ERR("Failed to get file size of %s\n", fname);
+        fclose(f);
+        return nullptr;
+    }
     buf.resize(file_size);
 
     size_t n_read = fread(buf.data(), 1, file_size, f);