# DF-2444 VERDICT

**Status:** reproduced
**Impact:** none
**Confidence:** certain

dm_dev_create on the EEXIST path hands out a pointer to freed memory: production call #1 (name df2444x) returned 0; production call #2 with the same name returned EEXIST (17) AND set the out-parameter dmv=0xfffff8008de708c0 - the object dm_dev_destroy just destroyed (dm_dev.c:264-267: destroy then *dmvp = dmv). Currently benign: the sole caller checks r != 0 and never touches *dmvp, so no corruption is reachable today; the defect is a latent caller-side UAF API hazard.

## Kernel references
- `sys/dev/disk/dm/dm_dev.c:264`
- `sys/dev/disk/dm/dm_dev.c:267`
- `sys/dev/disk/dm/dm_ioctl.c:213`

## Guest
DragonFly dfbsd 6.5-DEVELOPMENT DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026 root@dfbsd:/usr/obj/usr/src/sys/X86_64_GENERIC x86_64

## Notes
root-only ioctl surface (dmsetup)

## 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.