CVE-2026-89545
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.
Scoring
- Severity
- HIGH
- CVSS base score
- 7.8
- CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS probability
- 0.16%
- Published
- 2026-09-11
- Last modified
- 2026-09-13
Affected products
- Linux Linux
- Linux Linux
- Linux Linux
- Linux Linux
- Linux Linux
- Linux Linux