DF-1460

init_device discards product-ID mismatch error and reads uninitialized cap on smbus failure

Summary

init_device at cyapa.c:360-373: smbus_trans for CMD_QUERY_CAPABILITIES error not checked before strncmp at :365. Stack garbage cap->prod_ida printed via device_printf (5-byte info leak to dmesg). Also :371 error=smbus_trans overwrites ENXIO from :368 product-ID mismatch. Non-cyapa device at addr 0x67 can attach. Fix: check error, goto done on failure, preserve ENXIO.

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Severity: Info
Status: new
Bucket: Kernel memory leaks / uninitialized disclosure
Confidence: certain
Pass: 1 · GLM 5.2 first pass
CVSS 3.1: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U:C:L/I:N/A:N
CWE: CWE-754 Improper Check for Unusual or Exceptional Conditions
File: sys/dev/smbus/cyapa/cyapa.c
Lines: 360-373
Area: dev
Discovered: 2026-07-17
Updated: 2026-07-17

Team triage

untriaged

priority: — · owner: —

PoC verification

reproduced

Status: reproduced
Reproduced: yes
Impact: none
Confidence: certain
Tested: 2026-07-23 18:17:25
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: certain
Tested: 2026-07-23 18:17:25
Runtime: —
Kernel: combined build rc=0
fix.diff: findings/poc/DF-1460/fix.diff
Runner: df-bsd-pocrunner

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PoC verification

Evidence pack

findings/poc/DF-1460 · 1 files

File	Type	Description	Size
manifest.json	file		393 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/smbus/cyapa/cyapa.c:360: init_device discards product-ID mismatch and reads uninitialized cap

Verified recommended fix

Source-confirmed at sys/dev/smbus/cyapa/cyapa.c:360: init_device discards product-ID mismatch and reads uninitialized cap

Verdict

Source-confirmed at sys/dev/smbus/cyapa/cyapa.c:360: init_device discards product-ID mismatch and reads uninitialized cap