DF-1303

mlx_getslot uses firmware-reported me_max_commands as array bound without clamping to MLX_NSLOTS

Summary

mlx_getslot at mlx.c:1962: limit=sc->mlx_enq2->me_max_commands (u16 0-65535 from firmware DMA). Loop at :1975 for(slot=0;slot<limit;slot++) accesses sc->mlx_busycmd[slot] which is MLX_NSLOTS=256 entries. NO clamping anywhere. me_max_commands>256 -> OOB read (:1977)/write (:1981) past mlx_busycmd into mlx_busycmds/mlx_sysdrive[]. Malicious/buggy HBA. Fix: clamp limit to MLX_NSLOTS.

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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:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
CWE: CWE-129 Improper Validation of Array Index
File: sys/dev/raid/mlx/mlx.c
Lines: 1962-1981
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-1303/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-1303 · 2 files

File	Type	Description	Size
VERDICT.md	verdict	verification verdict	915 B	↓ raw
fix.diff	suggested-fix	git-apply-able fix	307 B	view raw

VERDICT.md verdict verification verdict

↓ download raw

DF-1303 - Verification Verdict

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

Finding

mlx_getslot uses firmware-reported me_max_commands as array bound without clamping to MLX_NSLOTS

Source Location

sys/dev/raid/mlx/mlx.c:1962-1981

Verdict

Source-confirmed: mlx_getslot uses firmware-reported me_max_commands as array bound with. 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

mlx_getslot at mlx.c:1962: limit=sc->mlx_enq2->me_max_commands (u16 0-65535 from firmware DMA). Loop at :1975 for(slot=0;slotmlx_busycmd[slot] which is MLX_NSLOTS=256 entries. NO clamping anywhere. me_max_commands>256 -> OOB read (:1977)/write (:1981) past mlx_busycmd into mlx_busycmds/mlx_sysdrive[]. Malicious/buggy HBA. Fix: clamp limit to MLX_NSLOTS.

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: mlx_getslot uses firmware-reported me_max_commands as array bound without clamping to MLX_NSLOTS. Added >MLX_NSLOTS clamp. HW-gated.

Verified recommended fix

Source-confirmed: mlx_getslot uses firmware-reported me_max_commands as array bound without clamping to MLX_NSLOTS. Added >MLX_NSLOTS clamp. HW-gated.

Verdict

Source-confirmed: mlx_getslot uses firmware-reported me_max_commands as array bound without clamping to MLX_NSLOTS. Added >MLX_NSLOTS clamp. HW-gated.