# DF-1507 VERDICT

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

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

**Mechanism:** vkbd.c:347 int flag = ap->a_ioflag. Line 382 if (flag & O_NONBLOCK) and 447 same. O_NONBLOCK=0x4 (fcntl.h:71) but a_ioflag carries IO_NDELAY=0x10 (vnode.h:274) per devfs_fo_read/write (devfs_vnops.c:1

**Citation:** `sys/dev/misc/vkbd/vkbd.c:347-447`

**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.