open-nomad/.changelog/12039.txt

```release-note:security
Prevent panic in spread iterator during allocation stop. [CVE-2022-24684](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-24684)
```
scheduler: prevent panic in spread iterator during alloc stop The spread iterator can panic when processing an evaluation, resulting in an unrecoverable state in the cluster. Whenever a panicked server restarts and quorum is restored, the next server to dequeue the evaluation will panic. To trigger this state: * The job must have `max_parallel = 0` and a `canary >= 1`. * The job must not have a `spread` block. * The job must have a previous version. * The previous version must have a `spread` block and at least one failed allocation. In this scenario, the desired changes include `(place 1+) (stop 1+), (ignore n) (canary 1)`. Before the scheduler can place the canary allocation, it tries to find out which allocations can be stopped. This passes back through the stack so that we can determine previous-node penalties, etc. We call `SetJob` on the stack with the previous version of the job, which will include assessing the `spread` block (even though the results are unused). The task group spread info state from that pass through the spread iterator is not reset when we call `SetJob` again. When the new job version iterates over the `groupPropertySets`, it will get an empty `spreadAttributeMap`, resulting in an unexpected nil pointer dereference. This changeset resets the spread iterator internal state when setting the job, logging with a bypass around the bug in case we hit similar cases, and a test that panics the scheduler without the patch. 2022-02-02 18:26:05 +00:00			```release-note:security
			`Prevent panic in spread iterator during allocation stop. [CVE-2022-24684](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-24684)`
			```