CVE-2025-40340 drm/xe: Fix oops in xe_gem_fault when running core_hotunplug test.
A null pointer dereference in the Linux kernel's Xe GPU driver allows local attackers to cause a system crash via memory mapping operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40340?
CVE-2025-40340 is a vulnerability in Linux, published on 9 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2025-40340?
How do I fix CVE-2025-40340?
Apply the vendor's patch.
Is CVE-2025-40340 being exploited?
There is no known exploitation of CVE-2025-40340 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40340, DEBIAN-CVE-2025-40340, GHSA-c24v-836h-jr7p, ROOT-OS-DEBIAN-12-CVE-2025-40340, ROOT-OS-DEBIAN-13-CVE-2025-40340, ROOT-OS-UBUNTU-2204-CVE-2025-40340 and 2 more.