CVE-2024-26674

/// Technical description

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

x86/lib: Revert to _ASM_EXTABLE_UA() for {get,put}_user() fixups

During memory error injection test on kernels >= v6.4, the kernel panics

like below. However, this issue couldn't be reproduced on kernels <= v6.3.

mce: [Hardware Error]: CPU 296: Machine Check Exception: f Bank 1: bd80000000100134

mce: [Hardware Error]: RIP 10:<ffffffff821b9776> {__get_user_nocheck_4+0x6/0x20}

mce: [Hardware Error]: TSC 411a93533ed ADDR 346a8730040 MISC 86

mce: [Hardware Error]: PROCESSOR 0:a06d0 TIME 1706000767 SOCKET 1 APIC 211 microcode 80001490

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 MCA code can recover from an in-kernel #MC if the fixup type is

EX_TYPE_UACCESS, explicitly indicating that the kernel is attempting to

access userspace memory. However, if the f

/// 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