CVE-2026-72359: drm/xe: fix NPD in bo_meminfo()
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: fix NPD in bomeminfo()
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->memtype will result in a NULL pointer dereference.
Fix this by safely skipping purged BOs in bomeminfo, as they no longer consume any memory.
User is getting NPD on device resume, and possible theory is that in bomove(), 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)
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Linux kernel (drm/xe)to a version that resolves this vulnerability.Fixed in v2 (Sashiko) - Configuration
Fix the NULL pointer dereference by safely skipping purged BOs in bo_meminfo(), making the code handle the general case where ttm.resource is NULL instead of unconditionally accessing bo->ttm.resource->mem_type.
drm/xe bo_meminfo() = Add a safe NULL check to skip purged buffer objects whose ttm.resource is NULL