Subject: CVE-2024-41027: Fix userfaultfd_api to return EINVAL as expected

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

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

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

Fix userfaultfd_api to return EINVAL as expected

Currently if we request a feature that is not set in the Kernel config we
fail silently and return all the available features.  However, the man
page indicates we should return an EINVAL.

We need to fix this issue since we can end up with a Kernel warning should
a program request the feature UFFD_FEATURE_WP_UNPOPULATED on a kernel with
the config not set with this feature.

 [  200.812896] WARNING: CPU: 91 PID: 13634 at mm/memory.c:1660 zap_pte_range+0x43d/0x660
 [  200.820738] Modules linked in:
 [  200.869387] CPU: 91 PID: 13634 Comm: userfaultfd Kdump: loaded Not tainted 6.9.0-rc5+ #8
 [  200.877477] Hardware name: Dell Inc. PowerEdge R6525/0N7YGH, BIOS 2.7.3 03/30/2022
 [  200.885052] RIP: 0010:zap_pte_range+0x43d/0x660

The Linux kernel CVE team has assigned CVE-2024-41027 to this issue.

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

	Issue introduced in 5.7 with commit e06f1e1dd499 and fixed in 5.15.163 with commit 519547760f16
	Issue introduced in 5.7 with commit e06f1e1dd499 and fixed in 6.1.100 with commit 14875fd5f9bc
	Issue introduced in 5.7 with commit e06f1e1dd499 and fixed in 6.6.41 with commit cd94cac4069a
	Issue introduced in 5.7 with commit e06f1e1dd499 and fixed in 6.9.10 with commit 8111f902b7c9
	Issue introduced in 5.7 with commit e06f1e1dd499 and fixed in 6.10 with commit 1723f04caacb

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-2024-41027
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/userfaultfd.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/519547760f16eae7803d2658d9524bc5ba7a20a7
	https://git.kernel.org/stable/c/14875fd5f9bcf60ac5518c63bfb676ade44aa7c6
	https://git.kernel.org/stable/c/cd94cac4069a763ab5206be2c64c9a8beae590ba
	https://git.kernel.org/stable/c/8111f902b7c95d75fc80c7e577f5045886c6b384
	https://git.kernel.org/stable/c/1723f04caacb32cadc4e063725d836a0c4450694