CVE-2026-68435: LoongArch: Fix address space mismatch in kexec command line lookup

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-12 · updated 2026-10-30

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.

Affected products

Linux: 6.1 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux 7.2. Check the vendor advisory for mitigations.

References

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