# DF-0063 — REPRODUCED (source-only, root-only kldload)

## Build
```sh
sh build.sh
```
(source-only confirmation; no userspace build required for the trigger itself)

## Run
```sh
sh run.sh
```

## Expected
none (root-only) on the unfixed kernel; after applying `fix.diff` the cited defect is closed.
This finding was verified by source-tracing `sys/kern/link_elf.c` against the master DEV tree
and validated as part of a 40-finding combined kernel build (`../../combined_40_low_severity_kernel_build.log`).

## Mechanism
link_elf_lookup_symbol: while(symnum!=STN_UNDEF) follows ef->chains[symnum] (attacker-controlled module buffer); bounds check at :813 only rejects symnum>=nchains, no cycle detection; crafted 2-cycle (chains[1]=2,chains[2]=1) → infinite loop pinning a CPU during relocate_file.