# DF-3070 verification

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

Line-verified dead store: tmpfs_subr.c:1058 writes osize (loaded from aobj->size at :1055) back into aobj->size - a no-op; the surrounding cleanup (swap_pager_freespace/vm_object_page_remove over [nsize, osize)) shows the intent was aobj->size = nsize. Not userland-observable (no behavioral delta measurable from userspace; deallocate frees the whole object regardless), so no guest reproduction is possible - confirmed by inspection only. Latent trap for any future consumer trusting aobj->size after truncate; line identical in DragonFly master.

## Kernel references
- sys/vfs/tmpfs/tmpfs_subr.c:1055
- sys/vfs/tmpfs/tmpfs_subr.c:1058

## Fix
See fix.diff.

## 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.