CVE-2026-99209
CVE-2026-99209CVE-2026-99209
Description
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]
C
Scoring
| Last modified | 2026-10-28 |