# CVE-2026-89548

## Summary

- **CVE ID:** CVE-2026-89548
- **Severity:** HIGH
- **CVSS Score:** 7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 14, 2026

## Description

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

SUNRPC: always drain cache_cleaner before destroying a cache_detail

sunrpc_destroy_cache_detail() only cancels the global cache_cleaner
delayed_work when cache_list is empty.  During per-netns teardown
cache_list is never empty because init_net's caches remain registered,
so the cancel never fires.  After unlink, the caller proceeds to
cache_destroy_net() which kfrees the cache_detail while cache_clean()
may still hold a dangling pointer to it.  The result is a
use-after-free: cache_dequeue() takes cd->queue_lock on freed memory,
and cache_put() dereferences cd->cache_put as a function pointer from
freed slab.

Drop the list_empty guard so that cancel_delayed_work_sync() always
runs, ensuring any in-flight cache_clean() completes before the
cache_detail is freed.  Re-arm the cleaner afterwards if other caches
are still registered.

## Affected Products

- Linux — Linux (820f9442e711a81749e70c40f149fc54c4ce0ca8)
- Linux — Linux (3.4)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (5.10.270)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/9d44836f60c8c29bcdb1471fd9202387c642a890)
- [CNA](https://git.kernel.org/stable/c/2e861ce2aaa468351a6a47c4cbb4971ebb740c7b)
- [CNA](https://git.kernel.org/stable/c/3d60fdf951143d6ef4e352e2f8eb852286701726)
- [CNA](https://git.kernel.org/stable/c/f42d0fda0c67695db6bc704b04b7c10240805377)
- [CNA](https://git.kernel.org/stable/c/dec787a15c96a5665e9ffc61b429a6a4ab26e6b9)
- [CNA](https://git.kernel.org/stable/c/5eea874a696201c31e7c2d7badbfa0d90e9961b5)
- [CNA](https://git.kernel.org/stable/c/cf239de7fdcc8336259b01ea4bcf650dadad1040)
- [CNA](https://git.kernel.org/stable/c/6d74ecc2be120a0c300b224b7649fe93c0453714)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.13%
- **EPSS Percentile:** 2.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._