# CVE-2026-80592: samples/damon/mtier: fail early if address range parameters are invalid

> A local attacker with high privileges can trigger a kernel warning and potential instability by enabling the DAMON mtier sample module with invalid address parameters.

- **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:** 28 Aug 2026
- **Updated:** 28 Aug 2026
- **Also known as:** BELL-CVE-2026-80592, DEBIAN-CVE-2026-80592, GHSA-m63c-95f6-2rwg, UBUNTU-CVE-2026-80592

## What is CVE-2026-80592?

CVE-2026-80592 is a denial of service vulnerability in Linux, published on 28 Aug 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:

samples/damon/mtier: fail early if address range parameters are invalid

The comment on top of `struct damon_region` clearly says that

    For any use case, @ar should be non-zero positive size.

which is now verified in damon_verify_new_region() if the kernel is built
with DAMON_DEBUG_SANITY.

The WARN_ONCE() can be triggered if the mtier sample module is enabled
before node{0,1}_{start,end}_addr have been properly initialized, which is
obviously not good.

 ------------[ cut here ]------------
 start 0 >= end 0
 WARNING: mm/damon/core.c:217 at damon_new_region+0xf4/0x118, CPU#59: bash/341468
 Call trace:
  damon_new_region+0xf4/0x118 (P)
  damon_set_regions+0xfc/0x3c0
  damon_sample_mtier_build_ctx+0xe8/0x3a8
  damon_sample_mtier_start+0x1c/0x90
  damon_sample_mtier_enable_store+0x98/0xb0
  param_attr_store+0xb4/0x128
  module_attr_store+0x2c/0x50
  sysfs_kf_write+0x58/0x90
  kernfs_fop_write_iter+0x16c/0x238
  vfs_write+0x2c0/0x370
  ksys_write+0x74/0x118
  __arm64_sys_write+0x24/0x38
  invoke_syscall+0xa8/0x118
  el0_svc_common.constprop.0+0x48/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x54/0x370
  el0t_64_sync_handler+0xa0/0xe8
  el0t_64_sync+0x1ac/0x1b0
 ---[ end trace 0000000000000000 ]---

Note that the same issue can happen if detect_node_addresses is true, and
node 0 or 1 is memoryless.  Fix it together by checking the validity of
parameters right before damon_new_region() and fail early if they're
invalid.

## Which versions are affected by CVE-2026-80592?


## How do I fix CVE-2026-80592?

Apply the vendor's patch.

## Is CVE-2026-80592 being exploited?

There is no known exploitation of CVE-2026-80592 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80592 and fix it if it is affected.

What it is: CVE-2026-80592 is a denial of service vulnerability in Linux, published on 28 Aug 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-2026-80592 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-2026-80592/ (Markdown: https://insights.sbomify.com/CVE-2026-80592/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80592
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80592
- OSV: https://osv.dev/vulnerability/CVE-2026-80592

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80592/
Summaries are generated and may contain mistakes; the official description above is the record.