CVE-2026-64021: drm/xe/oa: Fix exec_queue leak on width check in stream open

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

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

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

drm/xe/oa: Fix exec_queue leak on width check in stream open

In xe_oa_stream_open_ioctl(), when param.exec_q->width > 1 the
function returns -EOPNOTSUPP directly, skipping the existing
err_exec_q cleanup path. The exec_queue reference obtained by
xe_exec_queue_lookup() is leaked.

The exec queue holds a reference on the xe_file, which is only
dropped during queue teardown. The leaked lookup ref is not on
the file's exec_queue xarray, so file close cannot release it.
This keeps both the exec queue and the file private state pinned
indefinitely.

Jump to err_exec_q instead of returning directly so the reference
is released.

(cherry picked from commit 339fa0be9e4a5d69fa47e91f4a36574224fb478f)

The Linux kernel CVE team has assigned CVE-2026-64021 to this issue.


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

	Issue introduced in 6.13 with commit f0ed39830e6064d62f9c5393505677a26569bb56 and fixed in 6.18.34 with commit 04ef7592eaadd9ca8f8f66e76452f73525cff819
	Issue introduced in 6.13 with commit f0ed39830e6064d62f9c5393505677a26569bb56 and fixed in 7.0.11 with commit 4b0c4f0c1b133d4bfa31c167200bcda646873328
	Issue introduced in 6.13 with commit f0ed39830e6064d62f9c5393505677a26569bb56 and fixed in 7.1 with commit 4d25342543c01310fc4e0cba7cb17c775e2421e2

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-2026-64021
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_oa.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/04ef7592eaadd9ca8f8f66e76452f73525cff819
	https://git.kernel.org/stable/c/4b0c4f0c1b133d4bfa31c167200bcda646873328
	https://git.kernel.org/stable/c/4d25342543c01310fc4e0cba7cb17c775e2421e2