CVE-2026-64080: firmware: arm_ffa: Snapshot notifier callbacks under lock

From: Greg Kroah-Hartman <[email protected]>

Description
===========

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

firmware: arm_ffa: Snapshot notifier callbacks under lock

Both notification handlers currently look up a notifier callback under
notify_lock, drop the lock, and then dereference the returned
notifier entry. A concurrent unregister can delete and free that
entry in the gap, leaving the handler to dereference stale memory.

Copy the callback pointer and callback data while notify_lock is
still held and invoke the callback only after the lock is dropped.
This keeps the existing callback execution model while removing the
use-after-free window in both the framework and non-framework
notification paths.

The Linux kernel CVE team has assigned CVE-2026-64080 to this issue.


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

	Issue introduced in 6.15 with commit 285a5ea0f542db94c3ed11e01a71abb47d15cbf5 and fixed in 6.18.34 with commit d1e38551fadea230649bc428f0f35c9ee062a072
	Issue introduced in 6.15 with commit 285a5ea0f542db94c3ed11e01a71abb47d15cbf5 and fixed in 7.0.11 with commit 0e7be42ef2490f19d859a6146324d48cafdc9d5c
	Issue introduced in 6.15 with commit 285a5ea0f542db94c3ed11e01a71abb47d15cbf5 and fixed in 7.1 with commit 38290b180a4d5746baed796d49f88d56d2f336cd

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-2026-64080
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:
	drivers/firmware/arm_ffa/driver.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/d1e38551fadea230649bc428f0f35c9ee062a072
	https://git.kernel.org/stable/c/0e7be42ef2490f19d859a6146324d48cafdc9d5c
	https://git.kernel.org/stable/c/38290b180a4d5746baed796d49f88d56d2f336cd