CVE-2025-22044

In the Linux kernel, the following vulnerability has been resolved:

acpi: nfit: fix narrowing conversion in acpi_nfit_ctl

Syzkaller has reported a warning in to_nfit_bus_uuid(): "only secondary bus families can be translated". This warning is emited if the argument is equal to NVDIMM_BUS_FAMILY_NFIT == 0. Function acpi_nfit_ctl() first verifies that a user-provided value call_pkg->nd_family of type u64 is not equal to 0. Then the value is converted to int, and only after that is compared to NVDIMM_BUS_FAMILY_MAX. This can lead to passing an invalid argument to acpi_nfit_ctl(), if call_pkg->nd_family is non-zero, while the lower 32 bits are zero.

Furthermore, it is best to return EINVAL immediately upon seeing the invalid user input. The WARNING is insufficient to prevent further undefined behavior based on other invalid user input.

All checks of the input value should be applied to the original variable call_pkg->nd_family.

[iweiny: update commit message]

This vulnerability is rated as Moderate severity because it requires local system access and primarily results in a denial of service via a kernel warning or crash. Exploitation is constrained to systems configured with ACPI-based Non-Volatile Dual In-line Memory Module (NVDIMM) hardware or emulated devices. Because the issue cannot be exploited remotely and does not allow privilege escalation or arbitrary code execution, overall risk to typical deployments is limited.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.