Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (nzxt-smart2) DMA-align output buffer
Sashiko reports:
When send_output_report() calls hid_hw_output_report(), the underlying USB HID core calls usb_interrupt_msg() which maps this buffer directly for DMA.
When the DMA mapping flushes or invalidates the cacheline, it will corrupt the adjacent variables (mutex, update_interval) that were modified concurrently by the CPU. This causes memory corruption due to cacheline sharing on non-coherent CPU architectures (such as ARM or MIPS). The DMA API debugging tool (CONFIG_DMA_API_DEBUG) will trigger runtime warnings for this violation.
Any operation that triggers send_output_report() (like setting a fan speed or updating the interval) causes the USB DMA mapping. On systems with non-coherent caches, this structural bug causes immediate and deterministic memory corruption.
Align the output buffer to ARCH_DMA_MINALIGN to fix the problem.
Details
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |