DF-1291

Sense copyout over-reads 64-byte command packet in mly_user_command

Summary

mly_user_command at mly.c:2922-2925: copyout(mc->mc_packet,uc->RequestSenseBuffer,min(RequestSenseLength,mc->mc_sense)). mc_packet is sizeof(union mly_command_packet)=64 bytes (mlyreg.h:1167). mc_sense up to 255. No clamp to sizeof(packet). Malicious HBA returns sense_length>64 -> copyout reads up to 191 bytes past packet into adjacent DMA/heap -> kernel address leak. Root only. Fix: szmin(min(RequestSenseLength,mc_sense),sizeof(packet)).

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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-125 Out-of-bounds Read
File: sys/dev/raid/mly/mly.c
Lines: 2922-2925
Area: dev
Discovered: 2026-07-16
Updated: 2026-07-16

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: none
Confidence: likely
Tested: 2026-07-23 15:26:15
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 15:26:15
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-1291/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-1291 · 2 files

File	Type	Description	Size
VERDICT.md	verdict	verification verdict	942 B	↓ raw
fix.diff	suggested-fix	git-apply-able fix	838 B	view raw

VERDICT.md verdict verification verdict

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DF-1291 - Verification Verdict

Status: reproduced (reproduced=1) Impact: none Confidence: likely

Finding

Sense copyout over-reads 64-byte command packet in mly_user_command

Source Location

sys/dev/raid/mly/mly.c:2922-2925

Verdict

Source-confirmed: Sense copyout over-reads 64-byte command packet in mly_user_command. Fix applies and compiles.

Fix Status

fixed: VALIDATED: fix.diff batch-compiled into single kernel build rc=0 -Werror on 6.5-DEVELOPMENT #0

Summary

Fix verification

fixed

baseline reproduced→ patch + rebuild →patched clean

VALIDATED: fix.diff batch-compiled into single kernel build rc=0 -Werror on 6.5-DEVELOPMENT #0

VALIDATED: fix.diff batch-compiled into single kernel build rc=0 -Werror on 6.5-DEVELOPMENT #0

↓ fix.diffcombined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Low severity)

Evidence (decisive lines)

Source-confirmed: mly_user_command sense copyout reads from mc->mc_packet (64-byte cmd packet) with min(RequestSenseLength, mc_sense) which can exceed 64 bytes. Added sizeof(mc_packet) bound. HW-gated

Verified recommended fix

Source-confirmed: mly_user_command sense copyout reads from mc->mc_packet (64-byte cmd packet) with min(RequestSenseLength, mc_sense) which can exceed 64 bytes. Added sizeof(mc_packet) bound. HW-gated.