# CVE-2026-90322: ocfs2/cluster: keep heartbeat local node stable

> A local attacker with high privileges can trigger a slab-out-of-bounds write in the OCFS2 cluster heartbeat module, potentially causing a system crash or arbitrary code execution.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-102906, BELL-CVE-2026-90322, DEBIAN-CVE-2026-90322, GHSA-p7qh-g4f5-gxq9, UBUNTU-CVE-2026-90322

## What is CVE-2026-90322?

CVE-2026-90322 is a memory corruption vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

ocfs2/cluster: keep heartbeat local node stable

o2nm_node_local_store() handles local=0 by stopping o2net and setting
cl_local_node to O2NM_INVALID_NODE_NUM, but it leaves cl_has_local set. 
That stale state makes o2nm_this_node() return 255, blocks a later local=1
attempt with -EBUSY, and can feed 255 to heartbeat users that call
o2nm_this_node() dynamically.

Clearing cl_has_local is required when the local node is reset.  But
heartbeat threads can still be running at that point.  They pin the local
node config item at startup, yet o2hb_do_disk_heartbeat() and thread
teardown re-read o2nm_this_node() for the local slot and for
o2nm_undepend_this_node().  Once local=0 has cleared the live local-node
state, those dynamic reads return O2NM_MAX_NODES, which is also the
invalid node number 255.

Store the local node number in the heartbeat region when the region
starts.  Use that stable node for heartbeat slot writes/checks,
negotiation messages, and the final configfs undepend.  Stop the heartbeat
loop when the current local node no longer matches the stored node, and
clear cl_has_local together with cl_local_node in the local=0 path so
nodemanager state matches node removal.

Validation reproduced this kernel report:
KASAN slab-out-of-bounds in o2hb_do_disk_heartbeat+0x372/0xb30
RIP: 0010:memset+0xf/0x20
Read of size 8
Call trace:
  dump_stack_lvl+0x66/0xa0
  print_report+0xd0/0x630
  o2hb_do_disk_heartbeat+0x372/0xb30 (fs/ocfs2/cluster/heartbeat.c:1079)
  srso_alias_return_thunk+0x5/0xfbef5
  __virt_addr_valid+0x188/0x2f0
  kasan_report+0xe4/0x120
  o2hb_do_disk_heartbeat+0x5/0xb30 (fs/ocfs2/cluster/heartbeat.c:1079)
  o2hb_thread+0x14e/0x770
  kthread_affine_node+0x139/0x180
  lockdep_hardirqs_on_prepare+0xda/0x190
  trace_hardirqs_on+0x18/0x130
  kthread+0x19d/0x1e0
  ret_from_fork+0x37a/0x4d0
  __switch_to+0x2d5/0x6f0
  ret_from_fork_asm+0x1a/0x30

## Which versions are affected by CVE-2026-90322?


## How do I fix CVE-2026-90322?

Apply the vendor's patch.

## Is CVE-2026-90322 being exploited?

There is no known exploitation of CVE-2026-90322 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90322 and fix it if it is affected.

What it is: CVE-2026-90322 is a memory corruption vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90322 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-90322/ (Markdown: https://insights.sbomify.com/CVE-2026-90322/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90322
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90322
- OSV: https://osv.dev/vulnerability/CVE-2026-90322

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90322/
Summaries are generated and may contain mistakes; the official description above is the record.