CVE-2026-72154 openrisc: Fix jump_label smp syncing
A race condition in OpenRISC jump_label SMP syncing allows stale instruction cache entries, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72154?
CVE-2026-72154 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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
Which versions are affected by CVE-2026-72154?
How do I fix CVE-2026-72154?
Apply the vendor's patch.
Is CVE-2026-72154 being exploited?
There is no known exploitation of CVE-2026-72154 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72154, DEBIAN-CVE-2026-72154, GHSA-w2g7-86j7-x792, UBUNTU-CVE-2026-72154.