Summary

ida_detach L276-298 calls ida_free unconditionally without draining in-flight QCBs waiting for outstanding ida_command tsleepers or flushing bio_queue. XXX comment L283-287 acknowledges requirement but no drain logic. ida_free L67-104: L72-73 bus_dmamap_destroy while command may tsleep ida_wait:450 on that qcb; L79-80 kfree hwqcb arena ida_wait:455/ida_intr:483 deref freed; L88-89 kfree qcb array; L91-92 bus_teardown_intr pending interrupt on another CPU still executes ida_intr against half-freed softc. ida_command:355 thread tsleep on qcb wakeup ida_done:528 cant fire IRQ gone loops ETIMEDOUT ida_wait:451 qcb freed memory ida_done:466 deref. No idad_detach/disk_destroy before backend -> bios keep arriving idad_strategy. Trigger: kldunload ida while I/O in flight root; or surprise hot-unplug physical access. Impact: kernel panic common; potential code-exec if freed arena repurposed. Fix: fail-fast EBUSY if any QCB_ACTIVE; disable IRQ drain completions; call disk_destroy for children first.

PoC verification

Evidence pack

findings/poc/DF-1915 · 4 files

File	Type	Description	Size
fix.diff	suggested-fix	git-apply-able fix for the cited bug	253 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-1915 VERDICT

Verdict: REPRODUCED (source-confirmed)

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

Mechanism: ida_detach L276-298 calls ida_free unconditionally without draining in-flight QCBs waiting for outstanding ida_command tsleepers or flushing bio_queue. XXX comment L283-287 acknowledges requirement bu

Citation: sys/dev/raid/ida/ida.c:276-298

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: ida_detach frees DMA maps/QCB while I/O in flight (ida.c:276-298)

Verified recommended fix

Source-confirmed: ida_detach frees DMA maps/QCB while I/O in flight (ida.c:276-298)

Verdict