jdhart81/poc-gguf-divzero-ne0

PoC: GGUF Parser Division-by-Zero (CWE-369)

Target: ggerganov/llama.cpp (ggml/src/gguf.cpp)
Severity: Medium (DoS - SIGFPE crash on x86/x86_64)
Commit: 6fce5c6 (2026-03-07)

Vulnerability

A crafted GGUF with tensor dimension ne[j]=0 triggers integer division by zero at gguf.cpp line 628. The validation checks ne[j] < 0 but misses ne[j] == 0.

Files

• poc_divzero.gguf - Malicious GGUF (ne[1]=0)
• poc_gguf_divzero.py - Python generator
• poc_divzero_standalone.c - Standalone C reproducer

Reproduction

```bash ./llama-cli -m poc_divzero.gguf # SIGFPE crash on x86

Or with UBSan: cmake -DLLAMA_SANITIZE_UNDEFINED=ON ..

```

Fix

```diff

• if (info.t.ne[j] < 0) {

• if (info.t.ne[j] <= 0) { ```