# CVE-2025-21745

## Summary

- **CVE ID:** CVE-2025-21745
- **Severity:** MEDIUM
- **CVSS Score:** 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** N/A
- **Published:** Feb 27, 2025
- **Last Modified:** Sep 8, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

blk-cgroup: Fix class @block_class's subsystem refcount leakage

blkcg_fill_root_iostats() iterates over @block_class's devices by
class_dev_iter_(init|next)(), but does not end iterating with
class_dev_iter_exit(), so causes the class's subsystem refcount leakage.

Fix by ending the iterating with class_dev_iter_exit().

## Affected Products

- Linux — Linux (ef45fe470e1e5410db4af87abc5d5055427945ac)
- Linux — Linux (5.9)
- Linux — Linux (0)
- Linux — Linux (5.10.235)
- Linux — Linux (5.15.179)
- Linux — Linux (6.1.129)
- Linux — Linux (6.6.78)
- Linux — Linux (6.12.14)
- Linux — Linux (6.13.3)
- Linux — Linux (6.14)

## References

- [CNA](https://git.kernel.org/stable/c/ffb494f1e7a047bd7a41b13796fcfb08fe5beafb)
- [CNA](https://git.kernel.org/stable/c/38287f779b34dfe959b4b681e909f2d3d52b88be)
- [CNA](https://git.kernel.org/stable/c/431b6ef2714be4d5babb802114987541a88b43b0)
- [CNA](https://git.kernel.org/stable/c/993121481b5a87829f1e8163f47158b72679f309)
- [CNA](https://git.kernel.org/stable/c/2ce09aabe009453d641a2ceb79e6461a2d4f3876)
- [CNA](https://git.kernel.org/stable/c/67c7f213e052b1aa6caba4a7e25e303bc6997126)
- [CNA](https://git.kernel.org/stable/c/d1248436cbef1f924c04255367ff4845ccd9025e)
- [CVE](https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html)
- [CVE](https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html)
- [siemens-SADP](https://cert-portal.siemens.com/productcert/html/ssa-265688.html)
- [siemens-SADP](https://cert-portal.siemens.com/productcert/html/ssa-082556.html)
- [siemens-SADP](https://cert-portal.siemens.com/productcert/html/ssa-019113.html)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.25%
- **EPSS Percentile:** 16.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._