In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work
hci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling
hci_uart_register_dev(), which calls proto->open() to initialize
hu->priv. However, if a TTY write wakeup occurs during this window,
hci_uart_tx_wakeup() may schedule write_work before hu->priv is
initialized, leading to a NULL pointer dereference in
hci_uart_write_work() when proto->dequeue() accesses hu->priv.
The race condition is:
CPU0 CPU1
---- ----
hci_uart_set_proto()
set_bit(HCI_UART_PROTO_INIT)
hci_uart_register_dev()
tty write wakeup
hci_uart_tty_wakeup()
hci_uart_tx_wakeup()
schedule_work(&hu->write_work)
proto->open(hu)
// initializes hu->priv
hci_uart_write_work()
hci_uart_dequeue()
proto->dequeue(hu)
// accesses hu->priv (NULL!)
Fix this by moving set_bit(HCI_UART_PROTO_INIT) after proto->open()
succeeds, ensuring hu->priv is initialized before any work can be
scheduled.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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)60 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 Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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