High severity · published Sep 11, 2026
CVE-2026-89548
SUNRPC: always drain cache_cleaner before destroying a cache_detail
7.8
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
820f9442e711a81749e70c40f149fc54c4ce0ca8 before dec787a15c96a5665e9ffc61b429a6a4ab26e6b9; 820f9442e711a81749e70c40f149fc54c4ce0ca8 before 5eea874a696201c31e7c2d7badbfa0d90e9961b5; 820f9442e711a81749e70c40f149fc54c4ce0ca8 before cf239de7fdcc8336259b01ea4bcf650dadad1040; 820f9442e711a81749e70c40f149fc54c4ce0ca8 before 6d74ecc2be120a0c300b224b7649fe93c0453714; 820f9442e711a81749e70c40f149fc54c4ce0ca8 before 9d44836f60c8c29bcdb1471fd9202387c642a890; 820f9442e711a81749e70c40f149fc54c4ce0ca8 before 2e861ce2aaa468351a6a47c4cbb4971ebb740c7b; +3 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-89548
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-89548
git.kernel.org
https://git.kernel.org/stable/c/2e861ce2aaa468351a6a47c4cbb4971ebb740c7b
git.kernel.org
https://git.kernel.org/stable/c/3d60fdf951143d6ef4e352e2f8eb852286701726
git.kernel.org
https://git.kernel.org/stable/c/5eea874a696201c31e7c2d7badbfa0d90e9961b5
git.kernel.org
https://git.kernel.org/stable/c/6d74ecc2be120a0c300b224b7649fe93c0453714
git.kernel.org
https://git.kernel.org/stable/c/9d44836f60c8c29bcdb1471fd9202387c642a890
git.kernel.org
https://git.kernel.org/stable/c/cf239de7fdcc8336259b01ea4bcf650dadad1040
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