# DF-2398 VERDICT

**Status:** reproduced (reproduced)
**Impact:** corruption
**Confidence:** certain
**Attempts:** 2

agp_generic_bind_memory aperture bounds check bypassed by 64-bit wraparound through the VERBATIM production code: control bind at 2x aperture correctly rejected (EINVAL, 0 chipset calls) while the wrap bind offset=0xfffffffffffff000 am_size=0x1000 (pg_start=0xFFFFFFFFFFFFF) PASSED the `offset + mem->am_size > AGP_GET_APERTURE()` check (sum wraps to 0) and invoked the chipset bind_page method at offset 0xfffffffffffff000 - far outside the 64MB aperture. The dead `offset < 0` test (vm_offset_t unsigned) confirmed. Fixed kernel rejects the wrap with EINVAL, 0 chipset calls.

## Kernel references
- `sys/dev/agp/agp.c:520`
- `sys/dev/agp/agp.c:522`
- `sys/dev/agp/agp.c:523`

## Guest
DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #7: Sat Oct 24 00:08:04 UTC 2026     root@dfbsd:/usr/obj/usr/src/sys/ACHARNESS  x86_64

## Fix validation
See fix.diff and README.md for the baseline/fixed A/B outputs (run.log / fixed.log).

## Fix status (batch validation)
Applied with the 36 sibling fix.diffs of this batch in findings/poc/_batch41/all_fixes.patch; single in-guest `make -j6 nativekernel KERNCONF=X86_64_GENERIC` completed RC=0 with zero errors under -Werror (full log: findings/poc/_batch41/fix_build8.log). Behavior A/B intentionally skipped for this Info-tier item.