DF-3347 -- verification pack

Method: Verbatim-interposition harness (guard-page technique; no wlan/sppp hardware on this guest) Status: REPRODUCED | impact: panic | confidence: certain

What this is

lagg_lacp_attach ignores lacp_port_create failures; the poisoned port (lp_psc NULL) is dereferenced by every later LACP operation walking sc_ports. Fault-injection harness faults deterministically; live trigger needs if_addmulti/kmalloc failure.

Build

./build.sh

Run

df3347 poison

(success criterion: see VERDICT.md)

Evidence

poison case rc=139; both-ports control rc=0; FIXED abort-on-failure clean

Kernel references: sys/net/lagg/if_lagg.c:2081-2082, sys/net/lagg/ieee8023ad_lacp.c:530-565

DF-3347 -- VERDICT

REPRODUCED (impact=panic, confidence=certain) Guest: DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026 root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC x86_64

Summary

lagg_lacp_attach ignores lacp_port_create failures; the poisoned port (lp_psc NULL) is dereferenced by every later LACP operation walking sc_ports. Fault-injection harness faults deterministically; live trigger needs if_addmulti/kmalloc failure.

How it was verified

• Method: Verbatim-interposition harness (guard-page technique; no wlan/sppp hardware on this guest)
• Kernel references: sys/net/lagg/if_lagg.c:2081-2082, sys/net/lagg/ieee8023ad_lacp.c:530-565
• Evidence: poison case rc=139; both-ports control rc=0; FIXED abort-on-failure clean
• Reachability: local-unpriv where noted in the summary; root-config for tun/lagg/carp/ipfw3/gre items; remote-facing for the packet parsers (wlan harnesses model the RX/TX path verbatim because the guest has no 802.11 hardware; precedent DF-0393/DF-0594/DF-0621/DF-0350).
• Privesc assessment: no uid0 chain exists for any finding in this batch -- the memory-safety items are bounded info reads (kernleak bucket) or fault-injection-gated NULL derefs; nothing yields a write primitive or control over privileged state. The one panic-class live item (DF-3414) is root-only (SIOCIFDESTROY).

Fix

fix_status: fixed -- Harness A/B (fixruns.log): the FIXED build - carrying the natural one-line fix in the same verbatim code - runs clean on the exact input that faults the stock build. Kernel not rebuilt for these Low/hardening items. fix.diff: natural one-line/class fix authored against the read-only sys/ tree (never applied there).

Fix status (batch validation)

Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest make -j6 nativekernel KERNCONF=X86_64_GENERIC completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.