# CVE-2026-23050: pNFS: Fix a deadlock when returning a delegation during open()

> A deadlock in the Linux kernel pNFS implementation allows a local attacker to cause a system hang during file open operations.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Feb 2026
- **Updated:** 11 May 2026
- **Also known as:** AZL-77139, BELL-CVE-2026-23050, DEBIAN-CVE-2026-23050, GHSA-pxjv-j4wf-pfw9, ROOT-OS-DEBIAN-11-CVE-2026-23050, ROOT-OS-DEBIAN-12-CVE-2026-23050, ROOT-OS-DEBIAN-13-CVE-2026-23050, ROOT-OS-UBUNTU-2204-CVE-2026-23050, ROOT-OS-UBUNTU-2404-CVE-2026-23050, UBUNTU-CVE-2026-23050

## What is CVE-2026-23050?

CVE-2026-23050 is a denial of service vulnerability in Linux, 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:

pNFS: Fix a deadlock when returning a delegation during open()

Ben Coddington reports seeing a hang in the following stack trace:
  0 [ffffd0b50e1774e0] __schedule at ffffffff9ca05415
  1 [ffffd0b50e177548] schedule at ffffffff9ca05717
  2 [ffffd0b50e177558] bit_wait at ffffffff9ca061e1
  3 [ffffd0b50e177568] __wait_on_bit at ffffffff9ca05cfb
  4 [ffffd0b50e1775c8] out_of_line_wait_on_bit at ffffffff9ca05ea5
  5 [ffffd0b50e177618] pnfs_roc at ffffffffc154207b [nfsv4]
  6 [ffffd0b50e1776b8] _nfs4_proc_delegreturn at ffffffffc1506586 [nfsv4]
  7 [ffffd0b50e177788] nfs4_proc_delegreturn at ffffffffc1507480 [nfsv4]
  8 [ffffd0b50e1777f8] nfs_do_return_delegation at ffffffffc1523e41 [nfsv4]
  9 [ffffd0b50e177838] nfs_inode_set_delegation at ffffffffc1524a75 [nfsv4]
 10 [ffffd0b50e177888] nfs4_process_delegation at ffffffffc14f41dd [nfsv4]
 11 [ffffd0b50e1778a0] _nfs4_opendata_to_nfs4_state at ffffffffc1503edf [nfsv4]
 12 [ffffd0b50e1778c0] _nfs4_open_and_get_state at ffffffffc1504e56 [nfsv4]
 13 [ffffd0b50e177978] _nfs4_do_open at ffffffffc15051b8 [nfsv4]
 14 [ffffd0b50e1779f8] nfs4_do_open at ffffffffc150559c [nfsv4]
 15 [ffffd0b50e177a80] nfs4_atomic_open at ffffffffc15057fb [nfsv4]
 16 [ffffd0b50e177ad0] nfs4_file_open at ffffffffc15219be [nfsv4]
 17 [ffffd0b50e177b78] do_dentry_open at ffffffff9c09e6ea
 18 [ffffd0b50e177ba8] vfs_open at ffffffff9c0a082e
 19 [ffffd0b50e177bd0] dentry_open at ffffffff9c0a0935

The issue is that the delegreturn is being asked to wait for a layout
return that cannot complete because a state recovery was initiated. The
state recovery cannot complete until the open() finishes processing the
delegations it was given.

The solution is to propagate the existing flags that indicate a
non-blocking call to the function pnfs_roc(), so that it knows not to
wait in this situation.

## Which versions are affected by CVE-2026-23050?


## How do I fix CVE-2026-23050?

Apply the vendor's patch.

## Is CVE-2026-23050 being exploited?

There is no known exploitation of CVE-2026-23050 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23050 and fix it if it is affected.

What it is: CVE-2026-23050 is a denial of service vulnerability in Linux, 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-2026-23050 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-2026-23050/ (Markdown: https://insights.sbomify.com/CVE-2026-23050/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23050
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23050
- OSV: https://osv.dev/vulnerability/CVE-2026-23050

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23050/
Summaries are generated and may contain mistakes; the official description above is the record.