CVE-2026-68298: drm/xe/vm: Fix SVM leak on resv obj alloc failure in xe_vm_create()

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

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

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

drm/xe/vm: Fix SVM leak on resv obj alloc failure in xe_vm_create()

Commit 9e9787414882 ("drm/xe/userptr: replace xe_hmm with gpusvm") made
xe_svm_init() unconditional in xe_vm_create() and extended it to also
initialize a "simple" gpusvm state for non-fault-mode VMs. The matching
xe_svm_fini() call in xe_vm_close_and_put() was updated to run
unconditionally, but the error unwind path in xe_vm_create() was not.

On the drm_gpuvm_resv_object_alloc() failure path, xe_svm_init() has
already succeeded but xe_svm_fini() is only called when
XE_VM_FLAG_FAULT_MODE is set. For non-fault-mode VMs this leaves
vm->svm.gpusvm partially initialized and leaks the resources allocated
by drm_gpusvm_init().

For fault-mode VMs, xe_svm_init() additionally acquires the pagemap
owner via drm_pagemap_acquire_owner() and the pagemaps via
xe_svm_get_pagemaps(). Those resources are released by xe_svm_close(),
not xe_svm_fini(). On the same error path, xe_svm_close() is not
called either, so fault-mode VMs leak the pagemap owner and pagemaps.

Fix both leaks:

- Call xe_svm_fini() unconditionally on the err_svm_fini path, matching
  the unconditional xe_svm_init() call. Move the vm->size = 0
  assignment out of the conditional so the xe_vm_is_closed() assert in
  xe_svm_fini() (and xe_svm_close()) holds for both modes.

- Call xe_svm_close() for fault-mode VMs before xe_svm_fini(), matching
  the ordering used in xe_vm_close_and_put().

(cherry picked from commit ca2a3587d577ba764e0fe628fb676244fc33ddd4)

The Linux kernel CVE team has assigned CVE-2026-68298 to this issue.


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

	Issue introduced in 6.18 with commit 9e978741488261e117bb50e5dfcf8e4080990958 and fixed in 6.18.42 with commit 279339aa8bdcf9db40094cf2bcbd495c53dbe817
	Issue introduced in 6.18 with commit 9e978741488261e117bb50e5dfcf8e4080990958 and fixed in 7.1.6 with commit 9ac92736030f3395d970c300eaeb59ac258a0c3e
	Issue introduced in 6.18 with commit 9e978741488261e117bb50e5dfcf8e4080990958 and fixed in 7.2-rc5 with commit d2c6800ad1802bed72a6de1416536737f114f1d6

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-2026-68298
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_vm.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/279339aa8bdcf9db40094cf2bcbd495c53dbe817
	https://git.kernel.org/stable/c/9ac92736030f3395d970c300eaeb59ac258a0c3e
	https://git.kernel.org/stable/c/d2c6800ad1802bed72a6de1416536737f114f1d6