# CVE-2026-90385: md/raid1: create serial pool adding rdev to array with serialize_policy=1

> A null pointer dereference in the Linux kernel RAID1 driver causes a system crash when adding a device to an array with serialization enabled.

- **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:** 17 Sep 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-102096, BELL-CVE-2026-90385, DEBIAN-CVE-2026-90385, GHSA-6jq9-46p7-p377, UBUNTU-CVE-2026-90385

## What is CVE-2026-90385?

CVE-2026-90385 is a vulnerability in Linux, published on 17 Sep 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:

md/raid1: create serial pool adding rdev to array with serialize_policy=1

The following bug has been observed with kernel 7.1.3 after adding a new
rdev to an existing RAID1 array with serialize_policy enabled:

  Oops: 0002 [#1]
  CPU: 0 UID: 0 PID: 19639 Comm: ext4lazyinit Not tainted 7.1.3-1-default
  RIP: _raw_spin_lock_irqsave+0x27/0x50
  CR2: 0000000000004960
  Call Trace:
   wait_for_serialization+0xb9/0x260 [raid1]
   raid1_make_request+0x762/0xaff [raid1]
   md_handle_request+0x1c9/0x2e0 [md_mod]

The raid1.c code calls wait_for_serialization() if the MD_SERIALIZE_POLICY
is set, and wait_for_serialization assumes that rdev->serial is
initialized. Normally this will be the case for arrays that have
the serialize_policy sysfs attribute set to 1.

But when a new rdev is added to an existing array in bind_rdev_to_array(),
the condition at mddev_create_serial_pool() causes creation of rdev->serial
to be skipped. Fix it.

## Which versions are affected by CVE-2026-90385?


## How do I fix CVE-2026-90385?

Apply the vendor's patch.

## Is CVE-2026-90385 being exploited?

There is no known exploitation of CVE-2026-90385 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90385 and fix it if it is affected.

What it is: CVE-2026-90385 is a vulnerability in Linux, published on 17 Sep 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-2026-90385 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-2026-90385/ (Markdown: https://insights.sbomify.com/CVE-2026-90385/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90385
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90385
- OSV: https://osv.dev/vulnerability/CVE-2026-90385

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90385/
Summaries are generated and may contain mistakes; the official description above is the record.