CVE-2026-80582: drm/shmem_helper: Check VMA boundaries for PMD mappings

CVE-2026-80582: drm/shmem_helper: Check VMA boundaries for PMD mappings

[Greg Kroah-Hartman]

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

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

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

drm/shmem_helper: Check VMA boundaries for PMD mappings

In the ->huge_fault handler do not install a PMD huge page
mapping if the huge page exceeds the boundaries of the VMA.

All other ->huge_fault handlers have similar checks and the
resulting mapping will trigger a VM_BUG_ON_VMA() if it ever
reaches copy_pmd_range().

The Linux kernel CVE team has assigned CVE-2026-80582 to this issue.


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

	Issue introduced in 7.0 with commit fc3bbf34e643faa8678aabdc3810c60109f3435a and fixed in 7.1.10 with commit 12803e89a1e593fd1e784dfe7453f5e392ccaff2
	Issue introduced in 7.0 with commit fc3bbf34e643faa8678aabdc3810c60109f3435a and fixed in 7.2 with commit 617bbd08714857c1613d7c550d43a9092ec0fb97

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-2026-80582
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_gem_shmem_helper.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/12803e89a1e593fd1e784dfe7453f5e392ccaff2
	https://git.kernel.org/stable/c/617bbd08714857c1613d7c550d43a9092ec0fb97