# CVE-2025-21817

## Summary

- **CVE ID:** CVE-2025-21817
- **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 7, 2026

## Description

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

block: mark GFP_NOIO around sysfs ->store()

sysfs ->store is called with queue freezed, meantime we have several
->store() callbacks(update_nr_requests, wbt, scheduler) to allocate
memory with GFP_KERNEL which may run into direct reclaim code path,
then potential deadlock can be caused.

Fix the issue by marking NOIO around sysfs ->store()

## Affected Products

- Linux — Linux (8985da5481562e96b95e94ed8e5cc9b6565eb82b)
- Linux — Linux (c99f66e4084a62a2cc401c4704a84328aeddc9ec)
- Linux — Linux (6.13.2)
- Linux — Linux (1645cd7fd42c236c952e9228badcac4fea1829ea)
- Linux — Linux (6.12.96)

## References

- [CNA](https://git.kernel.org/stable/c/2566ce907e5d5db8a039647208e029ce559baa31)
- [CNA](https://git.kernel.org/stable/c/7c0be4ead1f8f5f8be0803f347de0de81e3b8e1c)
- [CNA](https://git.kernel.org/stable/c/a09280c39ea54080daf19cfaf4a3121a8d17d5cd)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.15%
- **EPSS Percentile:** 4.3

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