# DF-1831 VERDICT

**Verdict:** REPRODUCED (source-confirmed)

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

**Mechanism:** ichwd_attach uses static global softc sc=&ichwd_sc but fail path reassigns sc=device_get_softc(dev) which for size-0 driver returns ZERO_LENGTH_PTR=(void*)-8 from kmalloc(0); first read sc->tco_res wr

**Citation:** `sys/dev/misc/ichwd/ichwd.c:603-604`

**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.