Summary

parityrebuild L367 stripe=pstripe/plex->stripesize L368 psd=plex->subdisks-1-stripe%plex->subdisks both integer divisions. Sole caller parityops L265 checks only isparity(plex) (organization>=plex_raid4) and plex->state never validates stripesize>0 or subdisks>0. Plex with organization=raid4/5 but stripesize=0 (or subdisks=0) reachable via inconsistent config/corrupted disk label/interrupted reconfig. L274 size=imin(DEFAULT_REVIVE_BLOCKSIZE,stripesize<<DEV_BSHIFT)=0 proceeds. Same divisor pattern in revive_block L99/109/113/116/118/120 (%stripesize) for striped/raid4/5 revive. Root-only VINUM_PARITYOP. Fix: validate stripesize>0&&subdisks>0 in parityops before calling parityrebuild.

PoC verification

Evidence pack

findings/poc/DF-1886 · 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	1.0 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-1886 VERDICT

Verdict: REPRODUCED (source-confirmed)

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

Mechanism: parityrebuild L367 stripe=pstripe/plex->stripesize L368 psd=plex->subdisks-1-stripe%plex->subdisks both integer divisions. Sole caller parityops L265 checks only isparity(plex) (organization>=plex_rai

Citation: sys/dev/raid/vinum/vinumrevive.c:116-382

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: div-by-zero when stripesize=0 or subdisks=0 (vinumrevive.c:367-368)

Verified recommended fix

Source-confirmed: div-by-zero when stripesize=0 or subdisks=0 (vinumrevive.c:367-368)

Verdict