In the Linux kernel, the following vulnerability has been resolved:
net/smc: fix use-after-free in smc_rx_pipe_buf_release()
smc_rx_splice() hands RMB pages to a pipe and takes a socket reference
per entry so the smc_sock stays alive until the reader finishes. The
connection does not: a concurrent close runs smc_conn_free(), which
releases the receive buffer back to the link group pool.
smc_rx_pipe_buf_release() tests sk_state before taking the socket lock.
The state can change between the test and the lock, and
smc_rx_update_cons() then dereferences conn->rmb_desc and walks
conn->lgr, which smc_conn_free() has already released. On the
is_reg_err path smcr_buf_unuse() frees the descriptor outright, so
this is a use-after-free.
Take the socket lock first and test conn->freed instead.
smc_conn_free() sets that flag before releasing anything, and every
caller holds the socket lock. The two paths exclude each other: either
the pipe release runs first with everything valid, or it sees the flag
and skips the update.
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