CVE-2026-64508

Technical Description

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

bpf: Support for hardening against JIT spraying

The BPF JIT allocator packs many small programs into larger executable

allocations and reuses space within those allocations as programs are

loaded and freed. When fresh code is written into space that a previous

program occupied, an indirect jump into the new program can reuse a branch

prediction left behind by the old one.

Flush the indirect branch predictors before reusing JIT memory so that

indirect jumps into a newly written program don't reuse predictions from an

old program that occupied the same space.

Introduce bpf_arch_pred_flush_enabled static key and bpf_arch_pred_flush

static call for flushing the branch predictors on JIT memory reuse.

Architectures that need a flush, can update it to a predictor flush

function. By default, its a NOP and does not emit any CALL.

Allocations larger than a pack are not covered by this flush. That is safe

because cBPF progra

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