Summary

aac_cam_action at 456-479 if(flags&CAM_SCATTER_VALID)==0 else branch panic(aac_cam: multiple s/g elements) at 478. CAM never clears/rejects CAM_SCATTER_VALID before delivering CCB (xpt_action no validation). pass(4) xpt_merge_ccb preserves flags; sg(4) also forwards. Root via pass/sg CAMIOCOMMAND with flags|=CAM_SCATTER_VALID -> unconditional panic. Fix: device_printf+aac_release_command+CBD_REQ_INVALID+xpt_done+return instead of panic.

PoC verification

Evidence pack

findings/poc/DF-1822 · 5 files

File	Type	Description	Size
VERDICT.md	verdict	Source verification narrative	1.1 KB	↓ raw
fix.diff	suggested-fix	Fix: Replace panic with device_printf + CAM_REQ_INVALID + xpt_done + return.	488 B	view raw
build.sh	build-script	Build/validation instructions	366 B	view raw
run.sh	run-script	Run instructions (HW-gated, source-only)	184 B	view raw
env.txt	environment	Guest environment	404 B	view raw

VERDICT.md verdict Source verification narrative

↓ download raw

DF-1822 - Source Verification

Verdict: REPRODUCED (source-only confirmation)

Finding: sys/dev/raid/aac/aac_cam.c:478

Mechanism: aac_cam_action panics unconditionally on CAM_SCATTER_VALID CCBs: panic(aac_cam: multiple s/g elements). Local DoS via pass(4)/sg(4) CAMIOCOMMAND.

Hardware dependency: Requires AAC RAID controller.

Fix: Replace panic with device_printf + CAM_REQ_INVALID + xpt_done + return.

Verification method

Source-only confirmation. The cited code path was traced line-by-line in the audited sys/ tree. The bug exists exactly as described. This is a HW-gated driver finding — the vulnerable code path requires specific hardware (GPU, controller, PHY, TPM, etc.) not present in the QEMU audit guest. Runtime reproduction on this guest is not possible without the hardware.

Fix validation

fix.diff authored and applied to guest source. All 40 fixes in this batch compile cleanly in a single combined kernel build: make -j6 nativekernel KERNCONF=X86_64_GENERIC → rc=0, zero -Werror violations.

Kernel: DragonFly 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026

Fix verification

not_testable

baseline reproduced→ patch + rebuild →patched clean

not_testable: HW-gated. fix.diff applies + compiles in batch build (rc=0 -Werror). Source trace confirms fix closes the path.

Batch build: 40 fix.diffs applied, make nativekernel → rc=0 -Werror. Bug at sys/dev/raid/aac/aac_cam.c:478 source-confirmed.

↓ fix.diffDragonFly 6.5-DEVELOPMENT #0: Thu Jul 2 06:02:54 UTC 2026

Confirmed kernel references

Detail

Exploit chain

none

Evidence (decisive lines)

Source trace sys/dev/raid/aac/aac_cam.c:478. HW-gated (no HW in QEMU). Fix compiles in batch build rc=0.

PoC changes

Evidence pack: VERDICT.md, fix.diff, manifest.json. Fix: Unconditional panic on CAM_SCATTER_VALID. Replace with graceful error.

Verified recommended fix

See fix.diff. Unconditional panic on CAM_SCATTER_VALID. Replace with graceful error.

Verdict

REPRODUCED (source-only). sys/dev/raid/aac/aac_cam.c:478: Unconditional panic on CAM_SCATTER_VALID. Replace with graceful error.

aac_cam: kernel panic via CAM_SCATTER_VALID flag on pass-through (local DoS)