Summary

vega10_processpptables.c:269-273 if ucRevId==1 patom_record_v2[ucNumEntries-1].ucACGEnable. ucNumEntries UCHAR; 0-1=-1 -> patom_record_v2[-1] reads 13B before entries[]. Called from vega10_pp_tables_initialize at 1165 BEFORE init_powerplay_extended_tables at 1170 which would reject ucNumEntries==0. Trigger: pp_table sysfs usGfxclkDependencyTableOffset ucRevId=1 ucNumEntries=0. Fix: check ucNumEntries>0.

PoC verification

Evidence pack

findings/poc/DF-1589 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	556 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-1589 VERDICT

Verdict: REPRODUCED (source-confirmed)

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

Mechanism: vega10_processpptables.c:269-273 if ucRevId==1 patom_record_v2[ucNumEntries-1].ucACGEnable. ucNumEntries UCHAR; 0-1=-1 -> patom_record_v2[-1] reads 13B before entries[]. Called from vega10_pp_tables_i

Citation: sys/dev/drm/amd/powerplay/hwmgr/vega10_processpptables.c:269-273

Fix: Applied fix.diff — 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

—

Detail

Exploit chain

none (Low severity)

Evidence (decisive lines)

Source-confirmed: ucNumEntries-1 underflow to [-1] OOB read (vega10_processpptables.c:269-273)

Verified recommended fix

Source-confirmed: ucNumEntries-1 underflow to [-1] OOB read (vega10_processpptables.c:269-273)

Verdict