DF-1322

NULL-pointer dereference at attach when Envy24 subsystem unknown and EEPROM absent

Summary

envy24_init at envy24.c:2409: sc->cfg=NULL. :2422 if NULL, cfg=envy24_rom2cfg(sc) which returns NULL if EEPROM absent/short (<GPIODIR+1) or I2C read fails. :2426 sc->adcn=((sc->cfg->scfg&ADC)>>2)+1 derefs NULL -> page fault panic. Triggered when subvendor/subdevice not in cfg_table AND no EEPROM. Malicious/defective Envy24 PCI device (hotplug). Fix: check cfg!=NULL after rom2cfg, return ENXIO.

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Severity: Low
Status: new
Bucket: Base system — drivers
Confidence: certain
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U:C:N/I:N/A:H
CWE: CWE-476 NULL Pointer Dereference
File: sys/dev/sound/pci/envy24.c
Lines: 2409-2426
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 15:26:16
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-1322/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-1322 · 2 files

File	Type	Description	Size
VERDICT.md	verdict	verification verdict	919 B	↓ raw
fix.diff	suggested-fix	git-apply-able fix	486 B	view raw

VERDICT.md verdict verification verdict

↓ download raw

DF-1322 - Verification Verdict

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

Finding

NULL-pointer dereference at attach when Envy24 subsystem unknown and EEPROM absent

Source Location

sys/dev/sound/pci/envy24.c:2409-2426

Verdict

Source-confirmed: NULL-pointer dereference at attach when Envy24 subsystem unknown and E. 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

envy24_init at envy24.c:2409: sc->cfg=NULL. :2422 if NULL, cfg=envy24_rom2cfg(sc) which returns NULL if EEPROM absent/short (adcn=((sc->cfg->scfg&ADC)>>2)+1 derefs NULL -> page fault panic. Triggered when subvendor/subdevice not in cfg_table AND no EEPROM. Malicious/defective Envy24 PCI device (hotplug). Fix: check cfg!=NULL after rom2cfg, return ENXIO.

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: envy24 attach sc->cfg can be NULL after envy24_rom2cfg when EEPROM absent, subsequent deref of sc->cfg->scfg causes NULL-deref. Added NULL check. HW-gated.

Verified recommended fix

Source-confirmed: envy24 attach sc->cfg can be NULL after envy24_rom2cfg when EEPROM absent, subsequent deref of sc->cfg->scfg causes NULL-deref. Added NULL check. HW-gated.

Verdict

Source-confirmed: envy24 attach sc->cfg can be NULL after envy24_rom2cfg when EEPROM absent, subsequent deref of sc->cfg->scfg causes NULL-deref. Added NULL check. HW-gated.