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

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

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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.

The Linux kernel CVE team has assigned CVE-2026-89745 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.19 with commit 651fdda8406d42a5004c5c79f269540a85d6a1ab and fixed in 7.2.4 with commit e7f6a6b5741d16fdac7adaecbe0fa52ae756f208
	Issue introduced in 6.19 with commit 651fdda8406d42a5004c5c79f269540a85d6a1ab and fixed in 7.3-rc1 with commit f81808de37338aac8e167f99bfae647b1b835c70

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-89745
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	fs/debugfs/file.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/e7f6a6b5741d16fdac7adaecbe0fa52ae756f208
	https://git.kernel.org/stable/c/f81808de37338aac8e167f99bfae647b1b835c70