# CVE-2026-98907: btrfs: protect sb_write_pointer() with invalidate lock


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 26 Oct 2026
- **Also known as:** AZL-110665, BELL-CVE-2026-98907, DEBIAN-CVE-2026-98907, GHSA-2r98-r7qj-j43v, UBUNTU-CVE-2026-98907

## What is CVE-2026-98907?

CVE-2026-98907 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

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

btrfs: protect sb_write_pointer() with invalidate lock

sb_write_pointer() reads the super block from the block device page cache
using read_cache_page_gfp(). This has the same race with BLKBSZSET as the
one fixed by commit 3f29d661e568 ("btrfs: sync read disk super and set
block size").

Take the mapping invalidate lock around read_cache_page_gfp() to
serialize the read against block size changes.

## Which versions are affected by CVE-2026-98907?


## How do I fix CVE-2026-98907?

Upgrade to a fixed version.

## Is CVE-2026-98907 being exploited?

There is no known exploitation of CVE-2026-98907 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98907 and fix it if it is affected.

What it is: CVE-2026-98907 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98907 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-2026-98907/ (Markdown: https://insights.sbomify.com/CVE-2026-98907/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98907
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98907
- OSV: https://osv.dev/vulnerability/CVE-2026-98907

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98907/
Summaries are generated and may contain mistakes; the official description above is the record.