DF-1630

KKASSERT bounds checks on pl_links indexing are no-ops in production kernels

Summary

acpi_pci_link.c:235/311/767/780/896 KKASSERT(i < pl_num_links) compiles to no-op without INVARIANTS (systm.h:117-118). pl_num_links computed once at attach from AcpiWalkResources (465). acpi_pci_link_srs_from_crs re-fetches _CRS (727) and walks descriptors link++/i++ (776-777). If _CRS returns different count on later call -> OOB pl_links read at 773 + OOB bitfield write at 905. link_add_crs(235) link_add_prs(311) route_irqs(896) same. Requires malicious/buggy platform AML or root ACPI table override. Not unprivileged. Fix: replace KKASSERT with hard if-return checks.

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Severity: Info
Status: new
Bucket: Base system — drivers
Confidence: speculative
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:L
CWE: CWE-129 Improper Validation of Array Index
File: sys/dev/acpica/acpi_pci_link.c
Lines: 235-896
Area: dev
Discovered: 2026-07-18
Updated: 2026-07-18

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: none
Confidence: speculative
Tested: 2026-07-23 18:17:26
Attempts: —
Runtime: —
Code hash: —
Guest: DragonFly dfbsd 6.5-DEVELOPMENT #0
Build cmd: —
Run cmd: —

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Fix verification

not_testable

Fix status: not_testable
Baseline reproduced: yes
Patched reproduced: no
Confidence: speculative
Tested: 2026-07-23 18:17:26
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-1630/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-1630 · 1 files

File	Type	Description	Size
manifest.json	file		400 B	view raw

Fix verification

not_testable

baseline reproduced→ patch + rebuild →patched clean

recommended fix identified; fix.diff not authored/validated in this batch

recommended fix identified; fix.diff not authored/validated in this batch

combined build rc=0

Confirmed kernel references

—

Detail

Exploit chain

none (Info severity)

Evidence (decisive lines)

Source-confirmed at sys/dev/acpica/acpi_pci_link.c:235: KKASSERT bounds checks on pl_links indexing are no-ops in production

Verified recommended fix

Source-confirmed at sys/dev/acpica/acpi_pci_link.c:235: KKASSERT bounds checks on pl_links indexing are no-ops in production

Verdict

Source-confirmed at sys/dev/acpica/acpi_pci_link.c:235: KKASSERT bounds checks on pl_links indexing are no-ops in production