CVE-2026-68435

Received Received - Intake

LoongArch Kernel kexec Command Line User Pointer Dereference

Publication date: 2026-08-12

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: Fix address space mismatch in kexec command line lookup When searching the loaded segments for the "kexec" command line marker, the kexec_load(2) path (file_mode == 0) passes the user-space segment buffer straight to strncmp() through a bogus (char __user *) cast. This dereferences a user pointer in kernel context, which is wrong and is flagged by sparse: arch/loongarch/kernel/machine_kexec.c:84:51: sparse: incorrect type in argument 2 (different address spaces) @@ expected char const * @@ got char [noderef] __user * Here copy the marker-sized prefix of each segment into a small on-stack buffer with copy_from_user() before comparing, and skip segments that fault. The subsequent copy_from_user() that stages the full command line into the safe area is left unchanged.

CVSS Scores

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Meta Information

Published

2026-08-12

Last Modified

2026-08-17

Generated

2026-09-01

AI Q&A

2026-08-12

EPSS Evaluated

2026-08-30

NVD

CVE-2026-68435

EUVD

EUVD-2026-57043

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a flaw in the kexec command line lookup for LoongArch systems. When loading a new kernel, the system incorrectly passes a user-space memory pointer to a kernel function without proper validation. This causes a type mismatch where the kernel tries to read user memory directly, which is unsafe and can lead to crashes or privilege escalation.

Detection Guidance

This vulnerability is specific to the Linux kernel's LoongArch architecture and involves a kernel memory corruption issue during kexec operations. Detection requires checking kernel logs for sparse warnings or kernel oops related to kexec command line handling. No direct network detection commands are applicable.

Impact Analysis

If exploited, this flaw could allow an attacker with local access to crash the system or potentially gain elevated privileges. It specifically affects systems using LoongArch architecture and the kexec feature for kernel updates.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it is a low-level kernel memory safety issue without documented impact on data protection or privacy controls.

Mitigation Strategies

Apply the latest kernel patch from your Linux distribution that resolves the LoongArch kexec command line lookup issue. Avoid using kexec_load(2) until patched. Monitor kernel logs for related errors after patching.

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