# DF-1571 VERDICT

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

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

**Mechanism:** xdisk.c:833-835 sc=dev->si_drv1 NULL check then sc->info.d_media_blocks deref NO lock. xa_terminate_check (656-680) takes xdisk_lk, kfree(sc) under lock. xa_size never serializes -> race window betwee

**Citation:** `sys/dev/disk/xdisk/xdisk.c:828-837`

**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.