In the Linux kernel, the following vulnerability has been resolved:
nfsd: clear CALLBACK_RUNNING on failed delegation recall queue
nfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit
at entry to serialize recall work, then calls nfsd4_run_cb() to queue
the recall. When the queue attempt fails the refcount bump is undone,
but the RUNNING bit is left set. The only site that clears the bit is
nfsd41_destroy_cb() (fs/nfsd/nfs4callback.c), which runs from the
workqueue and is therefore unreachable when nothing was queued.
The bit becomes a permanent latch on dp->dl_recall.cb_flags: every
subsequent break_lease() on the same delegation hits the early-return
guard in nfsd_break_one_deleg() and silently skips the recall, so the
delegation is never broken and the conflicting open or lock stalls.
Fix by clearing NFSD4_CALLBACK_RUNNING on the !queued branch alongside
the refcount_dec.
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