CVE-2026-72154

Received Received - Intake

OpenRISC Jump Label SMP Cache Syncing Fix

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: openrisc: Fix jump_label smp syncing The original commit 8c30b0018f9d ("openrisc: Add jump label support") copies from arm64 and does not properly consider how icache invalidation on remote cores works in OpenRISC. On OpenRISC remote icaches need to be invalidated otherwise static key's may remain state after updating. Fix SMP cache syncing by: 1. Properly invalidate remote core icaches on SMP systems by using icache_all_inv. The old code uses kick_all_cpus_sync() which runs a no-op IPI function call on remote CPU's which does execute a lot of code and flushes many cache lines in the process, but does not flush all and it's not correct on OpenRISC. 2. For architectures that do not have WRITETHROUGH caches be sure to flush the dcache after patching. To test this I first reproduced the issue using a custom test module [0]. The test confirmed that some icache lines maintained stale static_key code sequences after calling static_branch_enable(). After this patch there are no longer jump_label coherency issues. [0] https://github.com/stffrdhrn/or1k-utils/tree/master/tests/smp_static_key_test

CVSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-72154

EUVD

EUVD-2026-58912

Affected Vendors & Products

Vendor	Product	Version / Range
openrisc	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel affects the OpenRISC architecture. It involves improper handling of instruction cache (icache) invalidation during SMP (symmetric multiprocessing) operations. When static keys are updated, remote CPU cores may retain stale code in their icaches, leading to potential inconsistencies in kernel execution paths.

Detection Guidance

This vulnerability is specific to the OpenRISC architecture in the Linux kernel and relates to icache invalidation issues during static key updates. Detection requires kernel-level inspection rather than network scanning. Check if your system uses OpenRISC architecture and examine kernel logs for static key-related errors or icache coherency issues during SMP operations.

Impact Analysis

This vulnerability could cause kernel instability or incorrect behavior on OpenRISC-based systems with multiple CPU cores. It may lead to crashes, data corruption, or security issues if stale kernel code executes after updates. Systems using static keys for feature toggles or performance optimizations are most affected.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a low-level kernel issue related to icache invalidation in OpenRISC architectures, which could lead to incorrect execution of static keys but does not involve data handling, privacy, or security controls typically regulated by these standards.

Mitigation Strategies

Apply the kernel patch that fixes the icache invalidation issue for OpenRISC. Update to a Linux kernel version that includes the fix for commit 8c30b0018f9d or later. If using a custom kernel, ensure proper icache_all_inv implementation is present for OpenRISC SMP systems.

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