CVE-2026-89545

sunrpc: defer rq_argp and rq_resp free until after RCU grace period

State: Published
Severity: 7.8 High
Published: Sep 11, 2026
Updated: Oct 30, 2026
Reserved: Sep 11, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	812443865c5fc255363d4a684a62c086af1addca to before c977158237bccc3d2512d5b17c47ee3760dc8839Affected 812443865c5fc255363d4a684a62c086af1addca to before 0ea49d69aa806008b2424c8cf21cf746b9963967Affected 812443865c5fc255363d4a684a62c086af1addca to before 08bc49e0541260bf294962cf889a32a2d2713ad6Affected 812443865c5fc255363d4a684a62c086af1addca to before e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090Affected 812443865c5fc255363d4a684a62c086af1addca to before c479bde671cbe2f9e152834a8b0eb7c3c295bbafAffected
LinuxLinux	3.19Affected before 3.19Not affected 6.1.191 through 6.1.Not affected 6.12.111 through 6.12.Not affected 6.18.50 through 6.18.Not affected 7.2.4 through 7.2.Not affected 7.3 and laterNot affected

Product

Versions

LinuxLinux

812443865c5fc255363d4a684a62c086af1addca to before c977158237bccc3d2512d5b17c47ee3760dc8839Affected
812443865c5fc255363d4a684a62c086af1addca to before 0ea49d69aa806008b2424c8cf21cf746b9963967Affected
812443865c5fc255363d4a684a62c086af1addca to before 08bc49e0541260bf294962cf889a32a2d2713ad6Affected
812443865c5fc255363d4a684a62c086af1addca to before e0c5693d3f9a5d4911735ab0e0eba4eecb1f1090Affected
812443865c5fc255363d4a684a62c086af1addca to before c479bde671cbe2f9e152834a8b0eb7c3c295bbafAffected

LinuxLinux

3.19Affected
before 3.19Not affected
6.1.191 through 6.1.*Not affected
6.12.111 through 6.12.*Not affected
6.18.50 through 6.18.*Not affected
7.2.4 through 7.2.*Not affected
7.3 and laterNot affected

References

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