Summary

mrsas_cam.c:482 req_desc NULL -> return FAIL no mrsas_release_mpt_cmd(cmd). 496 mrsas_build_ldio fail -> return(1) no release. 503 mrsas_build_dcdb fail -> return(1) no release. cmd never returned to pool. mrsas_map_request may have already bus_dmamap_load inside build helpers. Compare correct pattern at 457/466/472 which DO release. Slow-burn pool drain -> triggers DF-1619 NULL deref. Fix: mrsas_unmap_request+mrsas_release_mpt_cmd on each error path.

PoC verification

Evidence pack

findings/poc/DF-1620 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	1.0 KB	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-1620 VERDICT

Verdict: REPRODUCED (source-confirmed)

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

Mechanism: mrsas_cam.c:482 req_desc NULL -> return FAIL no mrsas_release_mpt_cmd(cmd). 496 mrsas_build_ldio fail -> return(1) no release. 503 mrsas_build_dcdb fail -> return(1) no release. cmd never returned to

Citation: sys/dev/raid/mrsas/mrsas_cam.c:481-507

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: mrsas_startio leaks mrsas_mpt_cmd on build-fail paths (mrsas_cam.c:482-503)

Verified recommended fix

Source-confirmed: mrsas_startio leaks mrsas_mpt_cmd on build-fail paths (mrsas_cam.c:482-503)

Verdict