# CVE-2025-37920: xsk: Fix race condition in AF_XDP generic RX path

> A race condition in the Linux kernel's AF_XDP generic RX path allows concurrent access issues, potentially leading to system instability or denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 20 May 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-62598, AZL-69941, BELL-CVE-2025-37920, DEBIAN-CVE-2025-37920, GHSA-4qc6-52f6-6vgr, ROOT-OS-DEBIAN-11-CVE-2025-37920, ROOT-OS-DEBIAN-12-CVE-2025-37920, ROOT-OS-UBUNTU-2204-CVE-2025-37920, ROOT-OS-UBUNTU-2404-CVE-2025-37920, UBUNTU-CVE-2025-37920

## What is CVE-2025-37920?

CVE-2025-37920 is a high-severity vulnerability in Linux kernel, published on 20 May 2025. 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:

xsk: Fix race condition in AF_XDP generic RX path

Move rx_lock from xsk_socket to xsk_buff_pool.
Fix synchronization for shared umem mode in
generic RX path where multiple sockets share
single xsk_buff_pool.

RX queue is exclusive to xsk_socket, while FILL
queue can be shared between multiple sockets.
This could result in race condition where two
CPU cores access RX path of two different sockets
sharing the same umem.

Protect both queues by acquiring spinlock in shared
xsk_buff_pool.

Lock contention may be minimized in the future by some
per-thread FQ buffering.

It's safe and necessary to move spin_lock_bh(rx_lock)
after xsk_rcv_check():
* xs->pool and spinlock_init is synchronized by
  xsk_bind() -> xsk_is_bound() memory barriers.
* xsk_rcv_check() may return true at the moment
  of xsk_release() or xsk_unbind_dev(),
  however this will not cause any data races or
  race conditions. xsk_unbind_dev() removes xdp
  socket from all maps and waits for completion
  of all outstanding rx operations. Packets in
  RX path will either complete safely or drop.

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

## Which versions are affected by CVE-2025-37920?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-37920?

Apply the vendor's patch.

## Is CVE-2025-37920 being exploited?

There is no known exploitation of CVE-2025-37920 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-2025-37920 and fix it if it is affected.

What it is: CVE-2025-37920 is a high-severity vulnerability in Linux kernel, published on 20 May 2025. 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-2025-37920 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-2025-37920/ (Markdown: https://insights.sbomify.com/CVE-2025-37920/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37920
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37920
- OSV: https://osv.dev/vulnerability/CVE-2025-37920

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37920/
Summaries are generated and may contain mistakes; the official description above is the record.