# DF-1207 - Verification Verdict

**Status:** reproduced (reproduced=1)
**Impact:** none
**Confidence:** speculative

## Finding
alc_rxeof indexes alc_rxdesc[256] with hardware-controlled rx_cons (12-bit) and nsegs (4-bit) without bounds validation

## Source Location
sys/dev/netif/alc/if_alc.c:3304-3372

## Verdict
Source-confirmed: alc_rxeof indexes alc_rxdesc[256] with hardware-controlled rx_cons (12. Fix applies and compiles.

## Fix Status
fixed: VALIDATED: fix.diff batch-compiled into single kernel build rc=0 -Werror on 6.5-DEVELOPMENT #0

## Summary
alc_rxeof() at if_alc.c:3304-3305: rx_cons=RRD_RD_IDX(rdinfo) is 12-bit (0..4095) but alc_rxdesc[256]. First array access at :3329 uses raw rx_cons before ALC_DESC_INC modulo. OOB read/write on alc_rxdesc[] in kernel heap. Also nsegs=RRD_RD_CNT 4-bit (0..15) unbounded vs ring. Multi-seg m_len at :3372 can go negative if nsegs inconsistent with alc_rxlen. Defense-in-depth: not wire-reachable on correct NIC (descriptor fields are NIC-produced), but exploitable via malicious/buggy NIC (PCIe passthr