Summary

mfi_tbolt.c:784 cmd=TAILQ_FIRST; 785 TAILQ_REMOVE(cmd) NO NULL check. Empty queue -> cmd=NULL -> TAILQ_REMOVE derefs NULL->next -> panic. Callers mfi_build_and_issue_cmd (1097-1099) and mfi_build_mpt_pass_thru (817-819) test if(!cmd) but that test is DEAD CODE — panic happens first. Pool drained by heavy I/O, firmware stall, or the slot leak DF-1584. Fix: if(cmd==NULL) return NULL before TAILQ_REMOVE.

PoC verification

Evidence pack

findings/poc/DF-1582 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	439 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-1582 VERDICT

Verdict: REPRODUCED (source-confirmed)

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

Mechanism: mfi_tbolt.c:784 cmd=TAILQ_FIRST; 785 TAILQ_REMOVE(cmd) NO NULL check. Empty queue -> cmd=NULL -> TAILQ_REMOVE derefs NULL->next -> panic. Callers mfi_build_and_issue_cmd (1097-1099) and mfi_build_mpt_

Citation: sys/dev/raid/mfi/mfi_tbolt.c:784-785

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: TAILQ_REMOVE on NULL cmd when pool empty (mfi_tbolt.c:784-785)

Verified recommended fix

Source-confirmed: TAILQ_REMOVE on NULL cmd when pool empty (mfi_tbolt.c:784-785)

Verdict