CVE-2026-46250

/// Technical description

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

MIPS: Work around LLVM bug when gp is used as global register variable

On MIPS, __current_thread_info is defined as global register variable

locating in $gp, and is simply assigned with new address during kernel

relocation.

This however is broken with LLVM, which always restores $gp if it finds

$gp is clobbered in any form, including when intentionally through a

global register variable. This is against GCC's documentation[1], which

requires a callee-saved register used as global register variable not to

be restored if it's clobbered.

As a result, $gp will continue to point to the unrelocated kernel after

the epilog of relocate_kernel(), leading to an early crash in init_idle,

[ 0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000000000000000, epc == ffffffff81afada8, ra == ffffffff81afad90

[ 0.000000] Oops[#1]:

[ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Tainted: G W

/// 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