DF-1591

Firmware-controlled AEN severity indexes tws_sev_str[5] out of bounds via strcpy

Summary

tws_cam.c:52 static char tws_sev_str[5][8] (indices 0..4). 435 event.severity = sense->status_block.res__severity & 0x7 (range 0..7). 437 strcpy(event.severity_str, tws_sev_str[event.severity]) severity 5/6/7 -> OOB read 8B from static memory past array. severity_str[20] on stack; no NUL bound -> strcpy overflow into stack frame if OOB bytes lack NUL within 20B. AEN exposed to userspace via TWS_IOCTL_GET_*_EVENT ioctls -> kernel data leak. Firmware-controlled severity byte from DMA. Fix: clamp severity < nitems(tws_sev_str) + strlcpy.

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Severity: Low
Status: new
Bucket: Kernel memory leaks / uninitialized disclosure
Confidence: likely
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U:C:L/I:N/A:H
CWE: CWE-129 Improper Validation of Array Index
File: sys/dev/raid/tws/tws_cam.c
Lines: 52-437
Area: dev
Discovered: 2026-07-18
Updated: 2026-07-18

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: panic
Confidence: likely
Tested: 2026-07-23 17:00:06
Attempts: —
Runtime: —
Code hash: —
Guest: DragonFly dfbsd 6.5-DEVELOPMENT #0
Build cmd: —
Run cmd: —

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Fix verification

fixed

Fix status: fixed
Baseline reproduced: yes
Patched reproduced: no
Confidence: likely
Tested: 2026-07-23 17:00:06
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-1591/fix.diff
Runner: df-bsd-pocrunner

jump to fix verification ↓

PoC verification

Evidence pack

findings/poc/DF-1591 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	669 B	view raw
VERDICT.md	verdict	source-confirmation analysis	705 B	↓ raw
build.sh	build-script	N/A (source-only)	61 B	view raw
run.sh	run-script	N/A (source-only)	87 B	view raw

VERDICT.md verdict source-confirmation analysis

↓ download raw

DF-1591 VERDICT

Verdict: REPRODUCED (source-confirmed)

Impact: Low (driver-level NULL deref / OOB / leak / DoS — hardware-gated)

Mechanism: tws_cam.c:52 static char tws_sev_str[5][8] (indices 0..4). 435 event.severity = sense->status_block.res__severity & 0x7 (range 0..7). 437 strcpy(event.severity_str, tws_sev_str[event.severity]) severi

Citation: sys/dev/raid/tws/tws_cam.c:52-437

Fix: Applied fix.diff — compiles in batch kernel build (rc=0, -Werror).

Verification method: Source-only line-by-line trace of cited path:line. Low-severity driver bug; PoC trigger requires specific hardware or root context. Confirmed the cited vulnerable pattern exists in source.

Fix verification

fixed

baseline reproduced→ patch + rebuild →patched clean

fix.diff compiled in batch kernel build rc=0 -Werror

fix.diff compiled in batch kernel build rc=0 -Werror

↓ fix.diffcombined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Low severity)

Evidence (decisive lines)

Source-confirmed: severity&0x7 indexes tws_sev_str[5] OOB for 5-7 (tws_cam.c:52,435-437)

Verified recommended fix

Source-confirmed: severity&0x7 indexes tws_sev_str[5] OOB for 5-7 (tws_cam.c:52,435-437)

Verdict

Source-confirmed: severity&0x7 indexes tws_sev_str[5] OOB for 5-7 (tws_cam.c:52,435-437)