CVE-2025-40230

/// Technical description

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

mm: prevent poison consumption when splitting THP

When performing memory error injection on a THP (Transparent Huge Page)

mapped to userspace on an x86 server, the kernel panics with the following

trace. The expected behavior is to terminate the affected process instead

of panicking the kernel, as the x86 Machine Check code can recover from an

in-userspace #MC.

mce: [Hardware Error]: CPU 0: Machine Check Exception: f Bank 3: bd80000000070134

mce: [Hardware Error]: RIP 10:<ffffffff8372f8bc> {memchr_inv+0x4c/0xf0}

mce: [Hardware Error]: TSC afff7bbff88a ADDR 1d301b000 MISC 80 PPIN 1e741e77539027db

mce: [Hardware Error]: PROCESSOR 0:d06d0 TIME 1758093249 SOCKET 0 APIC 0 microcode 80000320

mce: [Hardware Error]: Run the above through 'mcelog --ascii'

mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel

Kernel panic - not syncing: Fatal local machine check

The root cause of this

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References