ggml-org/llama.cpp b11871

on GitHub

chat : reject JSON nested more than 128 levels before walking it (#30242)

• chat : reject JSON nested more than 128 levels before walking it

The schema builder, the jinja engine and the decision code walk request
JSON with recursion. A request nested deep enough overflows the stack of
the HTTP thread and llama-server dies (SIGBUS on macOS, SIGSEGV on Linux):
for a tool schema from a few hundred levels on macOS and about 10000 on
Linux.

Check the depth first and answer 400 past 128 levels: the chat inputs in
common_chat_templates_apply (tools, tool-call arguments,
chat_template_kwargs, json_schema), the json_schema of /completion, and the
whole /v1/systemone body. A gemma4 tool result that is too deep stays text.

• fix the root, not the call side

Co-authored-by: Xuan Son Nguyen son@huggingface.co