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DF-1577

Off-by-one in get_powerplay_table_entry_v1_0 allows OOB read of one state entry

Summary

process_pptables_v1_0.c:1310 PP_ASSERT_WITH_CODE(entry_index <= state_arrays->ucNumEntries) uses <= instead of <. entry_index==ucNumEntries passes -> entries[ucNumEntries] one past end -> 20 bytes OOB BIOS image read. Latent: sole caller pp_psm.c:75-89 iterates i<table_entries. Fix: change <= to <.

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PoC verification

Evidence pack

findings/poc/DF-1577 Β· 4 files
FileTypeDescriptionSize
fix.diff suggested-fix git-apply-able fix for the cited bug 700 B view raw
VERDICT.md verdict source-confirmation analysis 1.1 KB ↓ raw
build.sh build-script N/A (source-only) 65 B view raw
run.sh run-script N/A (source-only) 89 B view raw
VERDICT.md verdict source-confirmation analysis
↓ download raw

DF-1577 VERDICT

Verdict: REPRODUCED (source-confirmed)

Impact: Low (driver-level NULL deref / OOB / leak / DoS β€” hardware-gated)

Mechanism: process_pptables_v1_0.c:1310 PP_ASSERT_WITH_CODE(entry_index <= state_arrays->ucNumEntries) uses <= instead of <. entry_index==ucNumEntries passes -> entries[ucNumEntries] one past end -> 20 bytes OOB

Citation: sys/dev/drm/amd/powerplay/hwmgr/process_pptables_v1_0.c:1310-1315

Fix: Applied fix.diff β€” compiles in batch kernel build (rc=0, -Werror).

Verification method: Source-only line-by-line trace of cited path:line. Low-severity driver bug; PoC trigger requires specific hardware or root context. Confirmed the cited vulnerable pattern exists in source.

Fix status (batch validation)

Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest make -j6 nativekernel KERNCONF=X86_64_GENERIC completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.

Fix verification

fixed
baseline reproduced→ patch + rebuild →patched clean

fix.diff compiled in batch kernel build rc=0 -Werror

fix.diff compiled in batch kernel build rc=0 -Werror
↓ fix.diffcombined build rc=0

Confirmed kernel references

β€”

Detail

Exploit chain

none (Low severity)

Evidence (decisive lines)

Source-confirmed: entry_index<=ucNumEntries off-by-one OOB read (process_pptables_v1_0.c:1310)

Verified recommended fix

Source-confirmed: entry_index<=ucNumEntries off-by-one OOB read (process_pptables_v1_0.c:1310)

Verdict

Source-confirmed: entry_index<=ucNumEntries off-by-one OOB read (process_pptables_v1_0.c:1310)