DF-1339

Unvalidated NCQ error tag allows OOB read on ap_ccbs via malicious device log page

Summary

sili_port_read_ncq_error at sili.c:2138: err_slot=log->err_regs.type&ATA_LOG_10H_TYPE_TAG_MASK(0x1f)=0..31. ap_ccbs has sc_ncmds=31 entries (indices 0..30). tag=31 -> ap_ccbs[31] one past end -> OOB read ccb->ccb_slot, OOB deref ccb->ccb_prb -> wild pointer. Sibling of DF-1211 (ahci NCQ tag OOB). Malicious SATA device. Fix: check err_slot<sc_ncmds.

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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:N/UI:N/S:C/C:N/I:L/A:L
CWE: CWE-129 Improper Validation of Array Index
File: sys/dev/disk/sili/sili.c
Lines: 2138-2146
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 15:26:17
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 15:26:17
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-1339/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-1339 · 2 files

File	Type	Description	Size
VERDICT.md	verdict	verification verdict	870 B	↓ raw
fix.diff	suggested-fix	git-apply-able fix	605 B	view raw

VERDICT.md verdict verification verdict

↓ download raw

DF-1339 - Verification Verdict

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

Finding

Unvalidated NCQ error tag allows OOB read on ap_ccbs via malicious device log page

Source Location

sys/dev/disk/sili/sili.c:2138-2146

Verdict

Source-confirmed: Unvalidated NCQ error tag allows OOB read on ap_ccbs via malicious dev. 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: sili NCQ error recovery uses device-reported err_slot as index into ap_ccbs without bounds check. Added SILI_MAX_CMDS bound. HW-gated.

Verified recommended fix

Source-confirmed: sili NCQ error recovery uses device-reported err_slot as index into ap_ccbs without bounds check. Added SILI_MAX_CMDS bound. HW-gated.

Verdict

Source-confirmed: sili NCQ error recovery uses device-reported err_slot as index into ap_ccbs without bounds check. Added SILI_MAX_CMDS bound. HW-gated.