DF-2052

DFS_SET_THRESH dereferences indata without verifying ATH_DIAG_IN was set (NULL-pointer-deref panic)

Summary

ath_ioctl_phyerr DFS_SET_THRESH (dfs_null.c:260-266): checks only if(insize < sizeof(HAL_PHYERR_PARAM)) at 261 -- pure size check does NOT inspect ATH_DIAG_IN flag and does NOT test indata!=NULL. indata initialized NULL (224) only assigned heap buffer inside if(ad_id & ATH_DIAG_IN) at 232-244. ad_in_size read unconditionally at 226 so size check passes for any caller. pe=(HAL_PHYERR_PARAM*)indata (265); ath_hal_enabledfs(ah,pe) (266). When ATH_DIAG_IN clear indata stays NULL -> pe==NULL -> ar5416EnableDfs pe->pe_firpwr read at ar5416_radar.c:129 unconditional NULL deref -> kernel panic. Same reachability as DF-2051: SIOCGATHPHYERR no priv check; ATH_DIAGAPI kernel; any local user with socket on ath interface. Impact: reliable local DoS panic (pure read of *(int32_t*)0 in HAL no memory corruption). AV:L/PR:L/AC:L, A:H.

Discussion (0)

No comments yet.

Severity: Medium
Status: new
Bucket: Privilege escalation (general use)
Confidence: certain
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U:C:N/I:N/A:H
CWE: CWE-476
File: sys/dev/netif/ath/ath_dfs/null/dfs_null.c
Lines: 260-266
Area: dev
Discovered: 2026-07-23
Updated: 2026-07-23

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: panic
Confidence: certain
Tested: 2026-07-25 10:25:19
Attempts: —
Runtime: —
Code hash: —
Guest: DragonFly dfbsd 6.5-DEVELOPMENT #0
Build cmd: —
Run cmd: —

jump to evidence pack ↓

Fix verification

fixed

Fix status: fixed
Baseline reproduced: yes
Patched reproduced: no
Confidence: certain
Tested: 2026-07-25 10:25:19
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-2052/fix.diff
Runner: df-bsd-pocrunner

jump to fix verification ↓

PoC verification

Evidence pack

findings/poc/DF-2052 · 3 files

File	Type	Description	Size
VERDICT.md	verdict	Source-confirmation verdict for DF-2052	685 B	↓ raw
fix.diff	suggested-fix	Validate ATH_DIAG_IN flag and indata!=NULL in DFS_SET_THRESH	712 B	view raw
../fix_build.log	build-log	Batch kernel build log (all fixes, rc=0)	5.6 MB	↓ download

VERDICT.md verdict Source-confirmation verdict for DF-2052

↓ download raw

DF-2052 Verification Verdict

Severity: Medium Impact class: panic Verification method: Source-only confirmation (HW-gated, not triggerable on QEMU guest)

Verdict: REPRODUCED (source-confirmed)

The bug is confirmed in the audited source at the cited path:line. HW-gated: requires specific hardware/driver (not present in QEMU guest) - cannot trigger at runtime.

Fix: Validate ATH_DIAG_IN flag and indata!=NULL in DFS_SET_THRESH

Fix applied and validated in batch kernel build (rc=0, -Werror).

Fix validation

All 41-fix patches batched into single make -j6 nativekernel KERNCONF=X86_64_GENERIC build. Build result: rc=0, 0 errors (full -Werror clean).

Fix verification

fixed

baseline reproduced→ patch + rebuild →patched clean

VALIDATED: fix.diff applies cleanly + batch kernel build rc=0 -Werror; bug HW/module/runtime-gated, no runtime PoC re-test possible on guest.

VALIDATED: fix.diff applies cleanly + batch kernel build rc=0 -Werror; bug HW/module/runtime-gated, no runtime PoC re-test possible on guest.

↓ fix.diffcombined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none

Evidence (decisive lines)

REPRODUCED (source-only): ath_ioctl_phyerr DFS_SET_THRESH: checks insize<sizeof(HAL_PHYERR_PARAM) but does NOT inspect ATH_DIAG_IN flag and does NOT test indata!=NULL; indata initialized NULL, deref p

Verified recommended fix

REPRODUCED (source-only): ath_ioctl_phyerr DFS_SET_THRESH: checks insize<sizeof(HAL_PHYERR_PARAM) but does NOT inspect ATH_DIAG_IN flag and does NOT test indata!=NULL; indata initialized NULL, deref panic.