CVE-2025-68329

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tracing: Fix WARN_ON in tracing_buffers_mmap_close for split VMAs<br /> <br /> When a VMA is split (e.g., by partial munmap or MAP_FIXED), the kernel<br /> calls vm_ops-&gt;close on each portion. For trace buffer mappings, this<br /> results in ring_buffer_unmap() being called multiple times while<br /> ring_buffer_map() was only called once.<br /> <br /> This causes ring_buffer_unmap() to return -ENODEV on subsequent calls<br /> because user_mapped is already 0, triggering a WARN_ON.<br /> <br /> Trace buffer mappings cannot support partial mappings because the ring<br /> buffer structure requires the complete buffer including the meta page.<br /> <br /> Fix this by adding a may_split callback that returns -EINVAL to prevent<br /> VMA splits entirely.