CVE-2026-97617

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

ring-buffer: Check resize disabled before publishing the new subbuf order

ring buffer subbuf order set() stores the new order and only then walks the CPUs, returning -EBUSY if any of them has resizing disabled. A user mapped buffer has resizing disabled, and rb map vma() reads buffer->subbuf order without buffer->mutex, so an mmap of an already mapped CPU racing the failing order change sizes the mapping with the new order and inserts pages past the sub-buffer into the VMA.

Check the CPUs before storing the new order.