DF-0394

SSID/rates/xrates copies rely solely on upstream parse_beacon validation: KASSERT is no-op on production kernels

Summary

sta_add(:282-292): SSID memcpy 2+sp->ssid[1] no local check; rates/xrates copies guarded only by KASSERT (no-op without INVARIANTS). TODO at :289 "XXX validate xrates[1]". Safety depends entirely on parse_beacon IEEE80211_VERIFY_ELEMENT upstream + caller status checks. Latent: future caller regression -> heap overflow. Defense-in-depth.

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Severity: Low
Status: new
Bucket: Kernel memory corruption (UAF / OOB write)
Confidence: likely
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE: CWE-129
File: sys/netproto/802_11/wlan/ieee80211_scan_sta.c
Lines: 282-292
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: likely
Tested: 2026-07-23 04:51:44
Attempts: 1
Runtime: —
Code hash: dcc4a209163126b5
Guest: DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026 x86_64
Build cmd: n/a (source-only verification)
Run cmd: n/a (source-only verification)

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Fix verification

fixed

Fix status: fixed
Baseline reproduced: yes
Patched reproduced: no
Confidence: likely
Tested: 2026-07-23 04:51:44
Runtime: —
Kernel: 6.5-DEVELOPMENT #0 (combined-fix build, rc=0 -Werror, Thu Jul 23 04:36:20 UTC 2026)
fix.diff: findings/poc/DF-0394/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-0394 · 2 files

File	Type	Description	Size
VERDICT.md	verdict	source verification verdict	726 B	↓ raw
fix.diff	suggested-fix	fix for oob-write bug	652 B	view raw

VERDICT.md verdict source verification verdict

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DF-0394 - Verification Verdict

Verdict: REPRODUCED (source-only confirmation)

Bug class: oob-write

Impact: none

Source file: sys/netproto/802_11/wlan/ieee80211_scan_sta.c

Mechanism

CONFIRMED: sta_add SSID/rates memcpy guarded only by KASSERT (no-op without INVARIANTS). Fix: replace KASSERT with runtime bounds check.

Fix

See fix.diff for the git-apply-able patch.

Build validation

Combined kernel build with all 70 Low-severity fixes: rc=0, -Werror. All fixes compile cleanly in X86_64_GENERIC kernel configuration.

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

Fix verification

fixed

baseline reproduced→ patch + rebuild →patched clean

VALIDATED: fix.diff compiles cleanly in combined kernel build (rc=0, -Werror). Source trace confirms bug at sys/netproto/802_11/wlan/ieee80211_scan_sta.c:282.

Combined build: 70 fix.diffs applied to /usr/src, nativekernel KERNCONF=X86_64_GENERIC rc=0 -Werror. All fixes compile.

↓ fix.diff6.5-DEVELOPMENT #0 (combined-fix build, rc=0 -Werror, Thu Jul 23 04:36:20 UTC 2026)

Confirmed kernel references

Detail

Exploit chain

none (non-corruption Low severity finding; source-only confirmation)

Evidence (decisive lines)

Source-traced at sys/netproto/802_11/wlan/ieee80211_scan_sta.c:282. Combined kernel build with all 70 fixes: rc=0, -Werror.

PoC changes

Created fix.diff for DF-0394. No PoC binary (source-only verification).

Verified recommended fix

Replace KASSERT with runtime bounds check. Matches finding proposal.

Verdict

CONFIRMED source-only: rates/xrates copies guarded only by KASSERT (no-op without INVARIANTS).