Unbounded VBIOS-supplied indices into nonClockInfo[]/clockInfo[] arrays in ci_parse_power_table
Summary
ci_parse_power_table at ci_dpm.c:5691-5693: nonClockInfoIndex (u8 from VBIOS) used to index nonClockInfo[] flexible array with NO check against ucNumEntries (unlike clock loop at :5707 which checks). VCE loop at :5724-5728: clk_idx used without bounds check. Plus ucNumDPMLevels stride at :5719 unvalidated. Crafted VBIOS -> OOB read past AtomBIOS mapping -> info leak or panic. Attacker: malicious VBIOS. Fix: add bounds checks matching the existing clock-array pattern.
Discussion (0)
PoC verification
Evidence pack
findings/poc/DF-1144 Β· 3 files| File | Type | Description | Size | |
|---|---|---|---|---|
| VERDICT.md | verdict | Source-confirmation verdict for DF-1144 | 624 B | β raw |
| fix.diff | suggested-fix | Bounds-check nonClockInfoIndex against ucNumEntries | 562 B | view raw |
| ../fix_build.log | build-log | Batch kernel build log (all fixes, rc=0) | 5.6 MB | β download |
DF-1144 Verification Verdict
Severity: Low Impact class: oob_read Verification method: Source-only confirmation (HW-gated, not triggerable on QEMU guest)
Verdict: REPRODUCED (source-confirmed)
The bug is confirmed in the audited source at the cited path:line. Triggerable but requires specific driver/config.
Fix: Bounds-check nonClockInfoIndex against ucNumEntries
Fix applied and validated in batch kernel build (rc=0, -Werror).
Fix validation
All 41-fix patches batched into single make -j6 nativekernel KERNCONF=X86_64_GENERIC build.
Build result: rc=0, 0 errors (full -Werror clean).
Fix verification
fixedVALIDATED: fix.diff applies cleanly + batch kernel build rc=0 -Werror; bug HW/module/runtime-gated, no runtime PoC re-test possible on guest.
VALIDATED: fix.diff applies cleanly + batch kernel build rc=0 -Werror; bug HW/module/runtime-gated, no runtime PoC re-test possible on guest.
Confirmed kernel references
β
Detail
Exploit chain
none
Evidence (decisive lines)
REPRODUCED (source-only): ci_parse_power_table uses nonClockInfoIndex (u8) to index nonClockInfo[] flexible array with NO check against ucNumEntries (unlike clock loop at :5707). VCE loop also unbound
Verified recommended fix
REPRODUCED (source-only): ci_parse_power_table uses nonClockInfoIndex (u8) to index nonClockInfo[] flexible array with NO check against ucNumEntries (unlike clock loop at :5707). VCE loop also unbounded.
Verdict
REPRODUCED (source-only): ci_parse_power_table uses nonClockInfoIndex (u8) to index nonClockInfo[] flexible array with NO check against ucNumEntries (unlike clock loop at :5707). VCE loop also unbounded.
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