Bug 2532164 (CVE-2026-89545) - CVE-2026-89545 kernel: sunrpc: defer rq_argp and rq_resp free until after RCU grace period
Summary: CVE-2026-89545 kernel: sunrpc: defer rq_argp and rq_resp free until after RCU...
Keywords:
Status: NEW
Alias: CVE-2026-89545
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-11 21:03 UTC by OSIDB Bzimport
Modified: 2026-09-18 15:11 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-09-11 21:03:23 UTC
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.


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