# DF-1406 - Verification Verdict

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

## Finding
OOB read of sdtr_period_tbl[8] on non-Ultra controllers when sync_data upper nibble>=8

## Source Location
sys/dev/disk/advansys/advlib.c:1073-1073

## Verdict
Source-confirmed: OOB read of sdtr_period_tbl[8] on non-Ultra controllers when sync_data. 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
adv_sdtr_to_period_offset at advlib.c:1073: *period=sdtr_period_tbl[((sync_data>>4)&0xF)]. Non-Ultra table has 8 entries, mask 0xF permits 0-15. sdtr_period_tbl_size=8 available but unused. sync_data from EEPROM sdtr_data[]. Upper nibble>=8 -> reads 1-7B past array into adjacent sdtr_period_tbl_ultra. Wrong SDTR period negotiated. EEPROM-controlled. No user/remote path. Fix: clamp idx<sdtr_period_tbl_size.