CVE-2026-31785: drm/xe/xe_pagefault: Disallow writes to read-only VMAs

CVE-2026-31785: drm/xe/xe_pagefault: Disallow writes to read-only VMAs

[Greg Kroah-Hartman]

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

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

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

drm/xe/xe_pagefault: Disallow writes to read-only VMAs

The page fault handler should reject write/atomic access to read only
VMAs.  Add code to handle this in xe_pagefault_service after the VMA
lookup.

v2:
- Apply max line length (Matthew)

(cherry picked from commit 714ee6754ac5fa3dc078856a196a6b124cd797a0)

The Linux kernel CVE team has assigned CVE-2026-31785 to this issue.


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

	Issue introduced in 6.19 with commit fb544b8445080c6488a58c01022550adc0873283 and fixed in 6.19.12 with commit b656f040ed4ed2074dfb78072745b41d44368be0
	Issue introduced in 6.19 with commit fb544b8445080c6488a58c01022550adc0873283 and fixed in 7.0 with commit 6d192b4f2d644d15d9a9f1d33dab05af936f6540

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-2026-31785
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/xe/xe_pagefault.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/b656f040ed4ed2074dfb78072745b41d44368be0
	https://git.kernel.org/stable/c/6d192b4f2d644d15d9a9f1d33dab05af936f6540