# CVE-2026-23110: scsi: core: Wake up the error handler when final completions race against each other

> A race condition in the Linux kernel SCSI core can prevent the error handler from waking, causing I/O to hang and resulting in a denial of service.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** 4 Feb 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-77118, BELL-CVE-2026-23110, DEBIAN-CVE-2026-23110, GHSA-7p3h-gfr2-rwcv, ROOT-OS-UBUNTU-2204-CVE-2026-23110, ROOT-OS-UBUNTU-2404-CVE-2026-23110, UBUNTU-CVE-2026-23110

## What is CVE-2026-23110?

CVE-2026-23110 is a medium-severity vulnerability in Linux kernel, published on 4 Feb 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:

scsi: core: Wake up the error handler when final completions race against each other

The fragile ordering between marking commands completed or failed so
that the error handler only wakes when the last running command
completes or times out has race conditions. These race conditions can
cause the SCSI layer to fail to wake the error handler, leaving I/O
through the SCSI host stuck as the error state cannot advance.

First, there is an memory ordering issue within scsi_dec_host_busy().
The write which clears SCMD_STATE_INFLIGHT may be reordered with reads
counting in scsi_host_busy(). While the local CPU will see its own
write, reordering can allow other CPUs in scsi_dec_host_busy() or
scsi_eh_inc_host_failed() to see a raised busy count, causing no CPU to
see a host busy equal to the host_failed count.

This race condition can be prevented with a memory barrier on the error
path to force the write to be visible before counting host busy
commands.

Second, there is a general ordering issue with scsi_eh_inc_host_failed(). By
counting busy commands before incrementing host_failed, it can race with a
final command in scsi_dec_host_busy(), such that scsi_dec_host_busy() does
not see host_failed incremented but scsi_eh_inc_host_failed() counts busy
commands before SCMD_STATE_INFLIGHT is cleared by scsi_dec_host_busy(),
resulting in neither waking the error handler task.

This needs the call to scsi_host_busy() to be moved after host_failed is
incremented to close the race condition.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-23110?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23110?

Apply the vendor's patch.

## Is CVE-2026-23110 being exploited?

There is no known exploitation of CVE-2026-23110 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-2026-23110 and fix it if it is affected.

What it is: CVE-2026-23110 is a medium-severity vulnerability in Linux kernel, published on 4 Feb 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-2026-23110 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-2026-23110/ (Markdown: https://insights.sbomify.com/CVE-2026-23110/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23110
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23110
- OSV: https://osv.dev/vulnerability/CVE-2026-23110

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23110/
Summaries are generated and may contain mistakes; the official description above is the record.