# CVE-2026-72176: mm/damon/sysfs-schemes: put stats for scheme_add_dirs() internal error

> A local attacker can trigger a kernel crash via null pointer dereference in DAMON sysfs schemes due to incorrect error handling in directory setup.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** BELL-CVE-2026-72176, DEBIAN-CVE-2026-72176, GHSA-vpg8-qvx8-2ch6, UBUNTU-CVE-2026-72176

## What is CVE-2026-72176?

CVE-2026-72176 is a vulnerability in Linux, published on 15 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:

mm/damon/sysfs-schemes: put stats for scheme_add_dirs() internal error

damon_sysfs_scheme_add_dirs() setup the tried_regions directory after the
stats directory setup is completed.  When the tried_regions directory
setup is failed, the setup function ensures the reference for the tried
regions directory is released.  Hence the error path should put references
on setup succeeded directory objects, starting from the stats directory. 
However, the error path is putting the tried_regions directory instead of
the stats directory.

As a direct result, the stats directory object is leaked.  Worse yet, if
the tried_regions directory setup failed from the initial allocation, the
scheme->tried_regions field remains uninitialized.  The following
kobject_put(&scheme->tried_regions->kobj) call in the error path will
dereference the uninitialized memory.  The setup failures should not be
common.  But once it happens, the consequence is quite bad.

Fix this issue by correctly putting the stats directory instead of the
tried_regions directory.

The issue was discovered [1] by Sashiko.

## Which versions are affected by CVE-2026-72176?


## How do I fix CVE-2026-72176?

Apply the vendor's patch.

## Is CVE-2026-72176 being exploited?

There is no known exploitation of CVE-2026-72176 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72176 and fix it if it is affected.

What it is: CVE-2026-72176 is a vulnerability in Linux, published on 15 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-2026-72176 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-2026-72176/ (Markdown: https://insights.sbomify.com/CVE-2026-72176/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72176
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72176
- OSV: https://osv.dev/vulnerability/CVE-2026-72176

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72176/
Summaries are generated and may contain mistakes; the official description above is the record.