Description (CNA)
The NXP LPUART serial driver (drivers/serial/uart_mcux_lpuart.c), when CONFIG_UART_USE_RUNTIME_CONFIGURE is enabled, called LPUART_Deinit() at the start of mcux_lpuart_configure(), which disables the LPUART peripheral clocks. The requested configuration is validated only afterwards (in mcux_lpuart_configure_basic), and unsupported parity/data-bit/stop-bit/flow-control values return -ENOTSUP before the clock is re-enabled. As a result, a uart_configure() request with an unsupported configuration left the LPUART in a clock-disabled state; any subsequent access to LPUART registers (poll_out/poll_in, interrupt handling, or a later reconfigure) faults on the gated peripheral and escalates to a hard fault, crashing the system. uart_configure() is a Zephyr syscall whose verifier (z_vrfy_uart_configure) only checks that cfg is readable user memory and forwards the caller-supplied configuration unchanged, so an unprivileged userspace thread with access to an LPUART device can deterministically trigger the fault, a persistent system-wide denial of service. Introduced in v2.5.0 and present in all subsequent releases until this fix, which removes the LPUART_Deinit() call and instead only disables the transmitter/receiver, leaving the clock running.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| zephyrproject / zephyr | affected 3.7.0 before 4.3.1; affected 4.4.0 before 4.4.2 |
CWE
CWE-617
References
- https://github.com/zephyrproject-rtos/zephyr/commit/f56935c46fdf6559a20ad8484b29896ecac5808f
- https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-mw68-r353-m3vf
ADP enrichment
No English description supplied.
No references supplied.