High severity · published Sep 11, 2026
CVE-2026-89545
sunrpc: defer rq_argp and rq_resp free until after RCU grace period
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved: sunrpc: defer rq_argp and rq_resp free until after RCU grace period svc_rqst_free() frees rqstp->rq_argp and rqstp->rq_resp synchronously via kfree(), but defers the rqstp struct free via kfree_rcu(). After svc_exit_thread() calls list_del_rcu() and svc_rqst_free(), there is a window where RCU readers that started before list_del_rcu() can still traverse the thread list and find the rqstp. These readers (e.g. nfsd_nl_rpc_status_get_dumpit()) dereference rqstp->rq_argp, which has already been freed — a use-after-free. Fix this by moving the kfree of rq_argp and rq_resp into an explicit call_rcu() callback alongside the struct free. Resources not accessed by RCU readers (bvec, buffer pages, scratch folio, auth_data) remain synchronously freed.
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)0.2% · higher than 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
812443865c5fc255363d4a684a62c086af1addca before 0ea49d69aa806008b2424c8cf21cf746b9963967; 812443865c5fc255363d4a684a62c086af1addca before 08bc49e0541260bf294962cf889a32a2d2713ad6; 812443865c5fc255363d4a684a62c086af1addca before e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090; 812443865c5fc255363d4a684a62c086af1addca before c479bde671cbe2f9e152834a8b0eb7c3c295bbaf; 3.19 · source: vendor