# CVE-2025-71072: shmem: fix recovery on rename failures

> A flaw in the Linux kernel's shmem rename handling can cause a denial of service when memory is low, requiring a kernel patch.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jan 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-74420, BELL-CVE-2025-71072, DEBIAN-CVE-2025-71072, GHSA-2j2j-fmxq-39xm, ROOT-OS-UBUNTU-2404-CVE-2025-71072, UBUNTU-CVE-2025-71072

## What is CVE-2025-71072?

CVE-2025-71072 is a high-severity denial of service vulnerability in Linux kernel, published on 13 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

shmem: fix recovery on rename failures

maple_tree insertions can fail if we are seriously short on memory;
simple_offset_rename() does not recover well if it runs into that.
The same goes for simple_offset_rename_exchange().

Moreover, shmem_whiteout() expects that if it succeeds, the caller will
progress to d_move(), i.e. that shmem_rename2() won't fail past the
successful call of shmem_whiteout().

Not hard to fix, fortunately - mtree_store() can't fail if the index we
are trying to store into is already present in the tree as a singleton.

For simple_offset_rename_exchange() that's enough - we just need to be
careful about the order of operations.

For simple_offset_rename() solution is to preinsert the target into the
tree for new_dir; the rest can be done without any potentially failing
operations.

That preinsertion has to be done in shmem_rename2() rather than in
simple_offset_rename() itself - otherwise we'd need to deal with the
possibility of failure after successful shmem_whiteout().

## Which versions are affected by CVE-2025-71072?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-71072?

Apply the vendor's patch.

## Is CVE-2025-71072 being exploited?

There is no known exploitation of CVE-2025-71072 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-71072 and fix it if it is affected.

What it is: CVE-2025-71072 is a high-severity denial of service vulnerability in Linux kernel, published on 13 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-71072 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2025-71072/ (Markdown: https://insights.sbomify.com/CVE-2025-71072/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71072
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71072
- OSV: https://osv.dev/vulnerability/CVE-2025-71072

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71072/
Summaries are generated and may contain mistakes; the official description above is the record.