CVE-2024-26911: drm/buddy: Fix alloc_range() error handling code

CVE-2024-26911: drm/buddy: Fix alloc_range() error handling code

[Greg Kroah-Hartman]

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

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

drm/buddy: Fix alloc_range() error handling code

Few users have observed display corruption when they boot
the machine to KDE Plasma or playing games. We have root
caused the problem that whenever alloc_range() couldn't
find the required memory blocks the function was returning
SUCCESS in some of the corner cases.

The right approach would be if the total allocated size
is less than the required size, the function should
return -ENOSPC.

The Linux kernel CVE team has assigned CVE-2024-26911 to this issue.


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

	Issue introduced in 6.7 with commit 0a1844bf0b53 and fixed in 6.7.6 with commit 4b59c3fada06
	Issue introduced in 6.7 with commit 0a1844bf0b53 and fixed in 6.8 with commit 8746c6c9dfa3

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-2024-26911
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/gpu/drm/drm_buddy.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/4b59c3fada06e5e8010ef7700689c71986e667a2
	https://git.kernel.org/stable/c/8746c6c9dfa31d269c65dd52ab42fde0720b7d91