Bug 2562687 (CVE-2026-99209)

Summary: CVE-2026-99209 kernel: drm/xe: skip eviction of a BO with no resource
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 exploit this vulnerability to cause a Denial of Service (DoS) via a kernel crash. The issue occurs when evicting a graphics buffer object that lacks an assigned memory resource, causing the driver to dereference a NULL pointer and trigger a system panic.
 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 2026-10-28 10:49:15 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/xe: skip eviction of a BO with no resource

xe_evict_flags() switches on tbo->resource->mem_type to choose an
eviction placement. An xe BO can reach eviction with no ttm.resource,
e.g. an imported dma-buf BO whose resource was freed during teardown
while its attachment is still live: the exporter then invalidates it via
xe_dma_buf_move_notify() -> xe_bo_evict(), and the switch dereferences a
NULL resource and faults.

A BO with no resource has nothing placed or mapped, so there is nothing
to evict. Return an empty placement (num_placement = 0), mirroring the
handling already used for non-xe scatter-gather BOs just above;
ttm_bo_validate() then takes the pipeline-gutting path and returns 0.

Without the fix the xe_dma_buf@xe_test_dmabuf_move_notify_no_resource
dynamic live selftest will fail with below stack.

BUG: kernel NULL pointer dereference, address: 0000000000000010
RIP: 0010:xe_evict_flags+0xf4/0x140 [xe]
Call Trace:
 <TASK>
 xe_bo_evict+0x40/0xa0 [xe]
 ? ttm_bo_pipeline_gutting+0x71/0x180 [ttm]
 xe_test_dmabuf_move_notify_no_resource+0x182/0x440 [xe]
 xe_dma_buf_kunit+0x387/0x580 [xe]

v2: Add Fixes tag and failure info in commit text (Matt Brost)

(cherry picked from commit dbcfaac6331f1fcb0c2fe3ad3e9adb1e5d43ec0c)
Comment 1 gkamathe 2026-10-28 15:26:42 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-99209.mbox