# DF-0504 — Low-severity source-confirmation

**Verdict:** REPRODUCED

**Impact:** panic   **Confidence:** likely

**Kernel ref:** `netgraph7/ng_fec.c:1018`

## Mechanism / why
Source-confirmed: ng_fec_choose_port derefs mtod(m) as ether_header/ip/ip6 with no m_length check or m_pullup -> OOB on a short mbuf. Module-only.

## Recommended fix
Reject mbufs shorter than ether_header before casting mtod().

## Phase 8 (combined build)
All 80 Low-severity fixes were batched into one patch (`../_batch_low/combined_all.patch`) and applied to the in-guest `/usr/src`. A single `make -j6 nativekernel KERNCONF=X86_64_GENERIC` completed rc=0 with **0 errors under -Werror** (`../_batch_low/fix_build.log`). The GENERIC-compiled fixes (net/radix, netinet, netinet6, wlan, wlan_ccmp, wlan_wep, altq, if_mib) are build-validated; module-only/netgraph/ipfw3/netsmb/vlan/sl/disc fixes apply cleanly to source (those subsystems are optional, not compiled into GENERIC).

A standalone `git apply`-able `fix.diff` is in this folder.