CVE-2025-40340

Summary

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

drm/xe: Fix oops in xe_gem_fault when running core_hotunplug test.

I saw an oops in xe_gem_fault when running the xe-fast-feedback testlist against the realtime kernel without debug options enabled.

The panic happens after core_hotunplug unbind-rebind finishes. Presumably what happens is that a process mmaps, unlocks because of the FAULT_FLAG_RETRY_NOWAIT logic, has no process memory left, causing ttm_bo_vm_dummy_page() to return VM_FAULT_NOPAGE, since there was nothing left to populate, and then oopses in "mem_type_is_vram(tbo->resource->mem_type)" because tbo->resource is NULL.

It's convoluted, but fits the data and explains the oops after the test exits.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxdd08ebf6c3525a7ea2186e636df064ea47281987 < 99428bd6123d5676209dfb1d7a8f176cc830b665affected
LinuxLinuxdd08ebf6c3525a7ea2186e636df064ea47281987 < 29a3064f9c5a908aaf0b39cd6ed30374db11840daffected
LinuxLinuxdd08ebf6c3525a7ea2186e636df064ea47281987 < 1cda3c755bb7770be07d75949bb0f45fb88651f6affected
LinuxLinux6.8affected
LinuxLinux0 < 6.8unaffected
LinuxLinux6.12.58 <= 6.12.*unaffected
LinuxLinux6.17.8 <= 6.17.*unaffected
LinuxLinux6.18 <= *unaffected

Weaknesses

References