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) {
```
