DF-1579

Kernel stack info leak via uninitialized bytesReturned copyout

Summary

hptrr_osm_bsd.c:1236 HPT_U32 bytesReturned; no init. 1249 memset(&ioctl_args,0,sizeof(ioctl_args)) zeroes ioctl_args NOT bytesReturned. 1254 lpBytesReturned=&bytesReturned. 1279-1281 copyout(&bytesReturned,...,4) on every HPT_IOCTL_RESULT_OK. ldm closed-source blob (x86_64-elf.hptrr_lib.o.uu) cannot prove which codes fail to write. 4-byte kernel stack leak -> KASLR inference. Root only /dev/hptrr mode 0600. Twin of DF-1564 (hpt27xx). Fix: bytesReturned=0.

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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:L/AC:H/PR:H/UI:N/S:U:C:L/I:N/A:N
CWE: CWE-908 Use of Uninitialized Resource
File: sys/dev/raid/hptrr/hptrr_osm_bsd.c
Lines: 1236-1281
Area: dev
Discovered: 2026-07-18
Updated: 2026-07-18

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: leak
Confidence: likely
Tested: 2026-07-23 17:00:05
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 17:00:05
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-1579/fix.diff
Runner: df-bsd-pocrunner

jump to fix verification ↓

PoC verification

Evidence pack

findings/poc/DF-1579 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	387 B	view raw
VERDICT.md	verdict	source-confirmation analysis	716 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-1579 VERDICT

Verdict: REPRODUCED (source-confirmed)

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

Mechanism: hptrr_osm_bsd.c:1236 HPT_U32 bytesReturned; no init. 1249 memset(&ioctl_args,0,sizeof(ioctl_args)) zeroes ioctl_args NOT bytesReturned. 1254 lpBytesReturned=&bytesReturned. 1279-1281 copyout(&bytesRet

Citation: sys/dev/raid/hptrr/hptrr_osm_bsd.c:1236-1281

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: uninitialized bytesReturned copyout leaks 4B kernel stack (hptrr_osm_bsd.c:1236,1279)

Verified recommended fix

Source-confirmed: uninitialized bytesReturned copyout leaks 4B kernel stack (hptrr_osm_bsd.c:1236,1279)

Verdict

Source-confirmed: uninitialized bytesReturned copyout leaks 4B kernel stack (hptrr_osm_bsd.c:1236,1279)