In the Linux kernel, the following vulnerability has been resolved:
rust_binder: use a u64 stride when cleaning up the offsets array
Allocation's Drop walks the offsets array (binder_size_t = u64 entries),
cleaning up the objects, but it used usize instead of u64 for both the
stride and the per-entry read.
On 64-bit kernels (usize == u64) this is harmless, but on 32-bit kernels
it walks the 8-byte entries in 4-byte steps, iterating an N-entry array
2N times, and reads the always-zero high word as offset 0, cleaning up
the object at offset 0 N extra times. As a result the referenced node or
handle ends up with a lower reference count than it actually has (a
refcount over-decrement), and binder's reference accounting is corrupted;
for example, the owner can be notified of a strong reference release
(BR_RELEASE) even though references still remain.
Change the stride to u64, and read each entry as a u64, narrowing it to
usize with try_into().
On 32-bit ARM, when this over-decrement would drive a count below zero,
the driver's existing refcount guard refuses it and fires:
rust_binder: Failure: refcount underflow!
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