# DF-0245 — DF-0245 — Per-cpu `iowbytes` counter underflow via thread migration

See **VERDICT.md** for the full root-cause analysis and reachability.

## Reproduce
```sh
./build.sh && ./run.sh
```
(For DF-0245 the bug is confirmed at source level; on this QEMU guest the vulnerable
path is latent / timing-dependent — see VERDICT.md "Reachability".)

## Fix
`fix.diff` is a standalone `git apply\ -able` patch. Validated to apply clean
(`git apply --check`) and compile in a single all-fixes kernel build
(`all_fixes_build.log`, rc=0, no errors).