From 3adbef7776dff2a2ab2f0780d6c2fcad4dbff14b Mon Sep 17 00:00:00 2001 From: Ruikai Peng Date: Fri, 20 Mar 2026 17:17:58 +0800 Subject: [PATCH] model: assert nextn_predict_layers to prevent underflow (#20783) Address GHSA-645x-v54x-34w8. When nextn_predict_layers >= n_layer, n_layer - nextn_predict_layers can underflow (unsigned wrap), which corrupts n_layer_kv_from_start. Assert nextn_predict_layers immediately after parsing the GGUF key. Found-by: Pwno --- src/llama-model.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/src/llama-model.cpp b/src/llama-model.cpp index 85db938a7a..06e0645352 100644 --- a/src/llama-model.cpp +++ b/src/llama-model.cpp @@ -1673,6 +1673,7 @@ void llama_model::load_hparams(llama_model_loader & ml) { // NextN/MTP parameters (GLM-OCR) ml.get_key(LLM_KV_NEXTN_PREDICT_LAYERS, hparams.nextn_predict_layers, false); + GGML_ASSERT(hparams.nextn_predict_layers < hparams.n_layer && "nextn_predict_layers must be < n_layer"); // TODO: when MTP is implemented, this should probably be updated if needed hparams.n_layer_kv_from_start = hparams.n_layer - hparams.nextn_predict_layers; @@ -1706,6 +1707,7 @@ void llama_model::load_hparams(llama_model_loader & ml) { // NextN/MTP parameters ml.get_key(LLM_KV_NEXTN_PREDICT_LAYERS, hparams.nextn_predict_layers, false); + GGML_ASSERT(hparams.nextn_predict_layers < hparams.n_layer && "nextn_predict_layers must be < n_layer"); // TODO: when MTP is implemented, this should probably be updated if needed hparams.n_layer_kv_from_start = hparams.n_layer - hparams.nextn_predict_layers; @@ -1752,6 +1754,7 @@ void llama_model::load_hparams(llama_model_loader & ml) { // NextN/MTP parameters ml.get_key(LLM_KV_NEXTN_PREDICT_LAYERS, hparams.nextn_predict_layers, false); + GGML_ASSERT(hparams.nextn_predict_layers < hparams.n_layer && "nextn_predict_layers must be < n_layer"); // TODO: when MTP is implemented, this should probably be updated if needed hparams.n_layer_kv_from_start = hparams.n_layer - hparams.nextn_predict_layers; @@ -1926,6 +1929,7 @@ void llama_model::load_hparams(llama_model_loader & ml) { ml.get_key(LLM_KV_LEADING_DENSE_BLOCK_COUNT, hparams.n_layer_dense_lead, false); ml.get_key(LLM_KV_NEXTN_PREDICT_LAYERS, hparams.nextn_predict_layers, false); + GGML_ASSERT(hparams.nextn_predict_layers < hparams.n_layer && "nextn_predict_layers must be < n_layer"); switch (hparams.n_layer) { case 32: type = LLM_TYPE_30B_A3B; break; @@ -2108,6 +2112,7 @@ void llama_model::load_hparams(llama_model_loader & ml) { ml.get_key(LLM_KV_EXPERT_WEIGHTS_NORM, hparams.expert_weights_norm, false); ml.get_key(LLM_KV_EXPERT_GATING_FUNC, hparams.expert_gating_func); ml.get_key(LLM_KV_NEXTN_PREDICT_LAYERS, hparams.nextn_predict_layers, false); + GGML_ASSERT(hparams.nextn_predict_layers < hparams.n_layer && "nextn_predict_layers must be < n_layer"); // TODO: when MTP is implemented, this should probably be updated if needed hparams.n_layer_kv_from_start = hparams.n_layer - hparams.nextn_predict_layers;