Bug 2516489 (CVE-2026-72359)

Summary:	CVE-2026-72359 kernel: drm/xe: fix NPD in bo_meminfo()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's `drm/xe` graphics driver. A local user could trigger a NULL pointer dereference when querying memory statistics for a buffer object that has been purged. This issue arises because the driver attempts to access a NULL resource, which can lead to a system crash and result in a Denial of Service (DoS).	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-08-15 06:15:12 UTC

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

drm/xe: fix NPD in bo_meminfo()

When a buffer object is purged, its ttm.resource is set to NULL via the
TTM pipeline gutting flow. However, the BO remains in the client's
object list until userspace explicitly closes the GEM handle. If memory
stats are queried during this time, accessing bo->ttm.resource->mem_type
will result in a NULL pointer dereference.

Fix this by safely skipping purged BOs in bo_meminfo, as they no longer
consume any memory.

User is getting NPD on device resume, and possible theory is that in
bo_move(), if we need to evict something to SYSTEM to save the CCS state,
but the BO is marked as dontneed, this won't trigger a move but will
nuke the pages, leaving us with a NULL bo resource. And the meminfo()
doesn't look ready to handle a NULL resource.

v2 (Sashiko):
 - There could potentially be other cases where we might end up with a
   NULL resource, so make this a general NULL check for now.

(cherry picked from commit c9a8e7daa0afe3161111e27fd92176e608c7f186)

Comment 1 gkamathe 2026-08-18 13:45:15 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081513-CVE-2026-72359-c9fb@gregkh/T