CVE-2026-72154: openrisc: Fix jump_label smp syncing
In the Linux kernel, the following vulnerability has been resolved:
openrisc: Fix jumplabel 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 icacheallinv. The old code uses kickallcpussync() 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 statickey code sequences after calling staticbranchenable(). After this patch there are no longer jumplabel coherency issues.
[0] https://github.com/stffrdhrn/or1k-utils/tree/master/tests/smpstatickeytest
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72154?
The severity of CVE-2026-72154 is classified as risk 11.
How do I fix CVE-2026-72154?
To fix CVE-2026-72154, you should update your Linux kernel to the latest version that includes the patch for this vulnerability.
What systems are affected by CVE-2026-72154?
CVE-2026-72154 affects systems that utilize the OpenRISC architecture in the Linux kernel.
What is the impact of CVE-2026-72154?
The impact of CVE-2026-72154 involves potential issues with jump_label smp syncing that may cause instability or security vulnerabilities in OpenRISC systems.
Is there a public repository for information on CVE-2026-72154?
Yes, the details for CVE-2026-72154 can be found in the Linux kernel repositories where the patch updates are maintained.