DF-0467

Dead code in ip6_savecontrol: RTHDRDSTOPTS walk result discarded, RFC3542 semantics not implemented

Summary

Block guarded by IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS(:1173) walks ext-header chain via ip6_nexthdr(:1188-1199) to locate Routing header. Variables proto/off/nxt declared local(:1175), loop result never stored. Subsequent block(:1202-1320) re-walks from scratch treating every DSTOPTS header identically. RFC3542 pre-RH (RTHDRDSTOPTS) vs post-RH (DSTOPTS) distinction not implemented. Socket requesting RTHDRDSTOPTS receives nothing; socket requesting DSTOPTS receives both. RFC non-conformance, no security impact.

Discussion (0)

No comments yet.

Severity: Info
Status: new
Bucket: Base system — network stack
Confidence: certain
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U:C:N/I:N/A:N
CWE: CWE-1164
File: sys/netinet6/ip6_input.c
Lines: 1173-1200
Area: net
Discovered: 2026-07-01
Updated: 2026-07-01

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: none
Confidence: certain
Tested: 2026-07-23 18:17:14
Attempts: —
Runtime: —
Code hash: —
Guest: DragonFly dfbsd 6.5-DEVELOPMENT #0
Build cmd: —
Run cmd: —

jump to evidence pack ↓

Fix verification

not_testable

Fix status: not_testable
Baseline reproduced: yes
Patched reproduced: no
Confidence: certain
Tested: 2026-07-23 18:17:14
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-0467/fix.diff
Runner: df-bsd-pocrunner

jump to fix verification ↓

PoC verification

Evidence pack

findings/poc/DF-0467 · 1 files

File	Type	Description	Size
manifest.json	file		391 B	view raw

Fix verification

not_testable

baseline reproduced→ patch + rebuild →patched clean

recommended fix identified; fix.diff not authored/validated in this batch

recommended fix identified; fix.diff not authored/validated in this batch

combined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Info severity)

Evidence (decisive lines)

Source-confirmed at sys/netinet6/ip6_input.c:1173: dead code in ip6_savecontrol (RTHDRDSTOPTS walk result discarded)

Verified recommended fix

Source-confirmed at sys/netinet6/ip6_input.c:1173: dead code in ip6_savecontrol (RTHDRDSTOPTS walk result discarded)

Verdict

Source-confirmed at sys/netinet6/ip6_input.c:1173: dead code in ip6_savecontrol (RTHDRDSTOPTS walk result discarded)