{"id":"CVE-2026-99209","published":"2026-10-28T11:17:42.290","lastModified":"2026-10-28T11:17:42.290","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe: skip eviction of a BO with no resource\n\nxe_evict_flags() switches on tbo->resource->mem_type to choose an\neviction placement. An xe BO can reach eviction with no ttm.resource,\ne.g. an imported dma-buf BO whose resource was freed during teardown\nwhile its attachment is still live: the exporter then invalidates it via\nxe_dma_buf_move_notify() -> xe_bo_evict(), and the switch dereferences a\nNULL resource and faults.\n\nA BO with no resource has nothing placed or mapped, so there is nothing\nto evict. Return an empty placement (num_placement = 0), mirroring the\nhandling already used for non-xe scatter-gather BOs just above;\nttm_bo_validate() then takes the pipeline-gutting path and returns 0.\n\nWithout the fix the xe_dma_buf@xe_test_dmabuf_move_notify_no_resource\ndynamic live selftest will fail with below stack.\n\nBUG: kernel NULL pointer dereference, address: 0000000000000010\nRIP: 0010:xe_evict_flags+0xf4/0x140 [xe]\nCall Trace:\n <TASK>\n xe_bo_evict+0x40/0xa0 [xe]\n ? ttm_bo_pipeline_gutting+0x71/0x180 [ttm]\n xe_test_dmabuf_move_notify_no_resource+0x182/0x440 [xe]\n xe_dma_buf_kunit+0x387/0x580 [xe]\n\nv2: Add Fixes tag and failure info in commit text (Matt Brost)\n\n(cherry picked from commit dbcfaac6331f1fcb0c2fe3ad3e9adb1e5d43ec0c)","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/448e76cbdc6652ccd3ba337b7a6e1f028859f2ed","tags":[]},{"url":"https://git.kernel.org/stable/c/6046bb9cb2859e3d9bf939e4d6527f3827e1096f","tags":[]},{"url":"https://git.kernel.org/stable/c/b6499d19ade1f1e4a1e6b739abc8c815297c98b8","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}