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