# CVE-2026-72155: mtd: spi-nor: swp: Improve locking user experience

> A logic error in the Linux kernel SPI-NOR driver prevents unlocking specific locked blocks, requiring a patch to correct the lock length calculation.

- **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:** 23 Aug 2026
- **Also known as:** BELL-CVE-2026-72155, DEBIAN-CVE-2026-72155, GHSA-4g3m-gr2j-r4mp, UBUNTU-CVE-2026-72155

## What is CVE-2026-72155?

CVE-2026-72155 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:

mtd: spi-nor: swp: Improve locking user experience

In the case of the first block being locked (or the few first blocks),
if the user want to fully unlock the device it has two possibilities:
- either it asks to unlock the entire device, and this works;
- or it asks to unlock just the block(s) that are currently locked,
  which fails.

It fails because the conditions "can_be_top" and "can_be_bottom" are
true. Indeed, in this case, we unlock everything, so the TB bit does not
matter. However in the current implementation, use_top would be true (as
this is the favourite option) and lock_len, which in practice should be
reduced down to 0, is set to "nor->params->size - (ofs + len)" which is
a positive number. This is wrong.

An easy way is to simply add an extra condition. In the unlock() path,
if we can achieve the same result from both sides, it means we unlock
everything and lock_len must simply be 0. A comment is added to clarify
that logic.

## Which versions are affected by CVE-2026-72155?


## How do I fix CVE-2026-72155?

Apply the vendor's patch.

## Is CVE-2026-72155 being exploited?

There is no known exploitation of CVE-2026-72155 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72155 and fix it if it is affected.

What it is: CVE-2026-72155 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-2026-72155 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-2026-72155/ (Markdown: https://insights.sbomify.com/CVE-2026-72155/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72155
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72155
- OSV: https://osv.dev/vulnerability/CVE-2026-72155

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72155/
Summaries are generated and may contain mistakes; the official description above is the record.