CVE-2026-89745debugfs: Fix lockdown check for mmap_prepare

Official description

In the Linux kernel, the following vulnerability has been resolved: debugfs: Fix lockdown check for mmap_prepare Commit 651fdda8406d ("relay: update relay to use mmap_prepare") changed the `mmap` file operation to `mmap_prepare` for relayfs, but the lockdown check in debugfs was not updated accordingly. This prevents debugfs from being locked down when the kernel is in integrity mode if a file uses `mmap_prepare` but not `mmap`. Since the conversion to `mmap_prepare` across the kernel is not yet complete, update the lockdown check to look for both `mmap` and `mmap_prepare` to ensure comprehensive coverage.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/e7f6a6b5741d16fdac7adaecbe0fa52ae756f208
• https://git.kernel.org/stable/c/f81808de37338aac8e167f99bfae647b1b835c70