# DF-0637 — Low-severity source-confirmation

**Verdict:** NOT_REPRODUCED

**Impact:** none   **Confidence:** likely

**Kernel ref:** `netgraph7/tty/ng_tty.c:253`

## Mechanism / why
NOT REPRODUCED: ng_tty already uses ng_uncallout(&sc->chand, sc->node) in its shutdown path (ng_tty.c:253), so the claimed callout-after-free is mitigated; the netgraph7 callout-lifetime fix is present.

## Recommended fix
No code change needed: ng_uncallout already present at ng_tty.c:253.

## 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).