In the Linux kernel, the following vulnerability has been resolved:
svcrdma: wake sq waiters when the transport closes
Threads parked in svc_rdma_sq_wait() on sc_sq_ticket_wait or
sc_send_wait can hang indefinitely in TASK_UNINTERRUPTIBLE state
across transport teardown, pinning svc_xprt references and
blocking svc_rdma_free().
The close path sets XPT_CLOSE before invoking xpo_detach and both
wait_event predicates include an XPT_CLOSE term, but the
predicates are re-evaluated only on wakeup. sc_sq_ticket_wait has
no completion-driven wake path; it is advanced solely by the
chained ticket handoff inside svc_rdma_sq_wait() itself. Without
an explicit wake at close, parked threads never observe
XPT_CLOSE, hold their svc_xprt_get reference forever, and
svc_rdma_free() blocks on xpt_ref dropping to zero.
Two close entry points reach this transport. Local teardown runs
svc_rdma_detach() from svc_handle_xprt() -> svc_delete_xprt() ->
xpo_detach() on a worker thread. A remote disconnect arrives at
svc_rdma_cma_handler(), which calls svc_xprt_deferred_close():
that sets XPT_CLOSE and enqueues the transport but does not
access either RDMA waitqueue, so a worker already parked in
svc_rdma_sq_wait() never re-evaluates its predicate. With every
worker parked on this transport, no thread is available to run
the local teardown either, and the wake site there is
unreachable.
Introduce svc_rdma_xprt_deferred_close(), a thin svcrdma wrapper
that calls svc_xprt_deferred_close() and then wakes both
sc_sq_ticket_wait and sc_send_wait. Convert the svcrdma producers
that called svc_xprt_deferred_close() directly:
svc_rdma_cma_handler(), qp_event_handler(),
svc_rdma_post_send_err(), svc_rdma_wc_send(), the sendto drop
path, the rw completion error paths, and the recvfrom flush and
read-list error paths.
Wake both waitqueues from svc_rdma_detach() as well. The
synchronous svc_xprt_close() path (backchannel ENOTCONN, device
removal via svc_rdma_xprt_done) reaches detach without flowing
through svc_xprt_deferred_close() and therefore does not invoke
the new helper.
[ cel: add svc_rdma_xprt_deferred_close() to complete the fix ]
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-27). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it