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DF-1144

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.

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PoC verification

Evidence pack

findings/poc/DF-1144 Β· 3 files
FileTypeDescriptionSize
VERDICT.md verdict Source-confirmation verdict for DF-1144 624 B ↓ 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 ↓ download
VERDICT.md verdict Source-confirmation verdict for DF-1144
↓ download raw

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

fixed
baseline reproduced→ patch + rebuild →patched clean

VALIDATED: 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.
↓ fix.diffcombined build rc=0

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.