CVE-2026-99160

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

ring-buffer: Do not show buffer meta for CPUs without a buffer

The per cpu/cpuN/buffer meta files are created for every possible CPU, but buffer->buffers[cpu] is only allocated once that CPU comes online. Reading the file of a CPU that never came online dereferences a NULL cpu buffer in rbm start().

Fail the open with -ENODEV when the CPU has no buffer, as the other per CPU ring buffer interfaces do.