DF-4277

cbb_resume() error path NULLs irq_res/base_res and returns ENOMEM but leaves the driver attached with stale intrhand — subsequent cbb_detach/cbb_suspend dereference the NULL resources (kernel panic)

Summary

If bus_setup_intr fails on resume, cbb_resume releases and NULLs the resources and returns ENOMEM - but the device remains attached with intrhand stale and the event thread still running (reading socket registers through the released resource). Any later detach/suspend dereferences the NULL resource pointers - panic in rman/bus paths. Keep-resources-valid fix.

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Severity: Low
Status: new
Bucket: Base system — drivers
Confidence: certain
Pass: 2 · GLM 5.3 second 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-476
File: sys/dev/pccard/pccbb/pccbb.c
Lines: 1574-1583
Area: dev
Discovered: 2026-09-19
Updated: 2026-09-19

Team triage

untriaged

priority: — · owner: —

PoC verification

untested

Status: untested
Reproduced: no
Impact: cbb_resume() error path NULLs irq_res/base_res and returns ENOMEM but leaves the driver attached with stale intrhand and a live event thread - subsequent cbb_detach/cbb_suspend dereference the NULL resources (kernel panic in rman/bus paths).
Confidence: certain
Tested: 2026-09-19 03:31:37
Attempts: 0
Runtime: —
Code hash: —
Guest: —
Build cmd: —
Run cmd: —

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Fix verification

not_testable

Fix status: not_testable
Baseline reproduced: no
Patched reproduced: no
Confidence: certain
Tested: 2026-09-19 03:31:37
Runtime: —
Kernel: per-fix-DF-4277
fix.diff: findings/poc/DF-4277/fix.diff
Runner: df-bsd-reviewer

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PoC verification

Evidence pack

findings/poc/DF-4277 · 2 files

File	Type	Description	Size
README.md	file		169 B	↓ raw
verdict.json	file		1.1 KB	view raw

README.md file

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DF-4277 — pccbb resume error-path NULL-resource panic

Partial cleanup leaves stale intrhand; later detach/suspend dereference the NULLed resources. Hardware-gated.

Fix verification

not_testable

baseline no→ patch + rebuild →patched clean

on setup_intr failure, keep resources valid for later detach (do not release+NULL what teardown consumes), or fully detach the device

source-only

per-fix-DF-4277

Confirmed kernel references

Detail

Exploit chain

[]

Evidence (decisive lines)

pccbb.c:1574-1583 partial cleanup vs consumers at :293, :302-304, :1541

Verdict

source-verified; hardware-gated (no CardBus bridge on audit guest; rare resume-time interrupt re-establishment failure precondition)