CVE-2026-74551

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux53e68c20aeb1e23419bed811aa3a309ceda200f9 < 70ad543ce81f368411b6c721265a3b2d7ab4fda4affected
LinuxLinux53e68c20aeb1e23419bed811aa3a309ceda200f9 < 51a76bc1b8e717ee3fc0d84f15ac51490ca5f76faffected
LinuxLinux53e68c20aeb1e23419bed811aa3a309ceda200f9 < 2332d35aaf206c17acf848522817252732596676affected
LinuxLinux53e68c20aeb1e23419bed811aa3a309ceda200f9 < 6a2dbce5da2d2163a5b684acf68a0e54582ff0faaffected
LinuxLinux53e68c20aeb1e23419bed811aa3a309ceda200f9 < 080bbf42faf77e6489ab30d5114c5f8f6ccbb1b8affected
LinuxLinux5.17affected
LinuxLinux0 < 5.17unaffected
LinuxLinux6.6.151 <= 6.6.*unaffected
LinuxLinux6.12.103 <= 6.12.*unaffected
LinuxLinux6.18.44 <= 6.18.*unaffected
LinuxLinux7.1.8 <= 7.1.*unaffected
LinuxLinux7.2-rc6 <= *unaffected

Weaknesses

References