CVE-2025-37868 drm/xe/userptr: fix notifier vs folio deadlock
A race condition in the Linux kernel's DRM Xe driver can cause a deadlock, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-37868?
CVE-2025-37868 is a medium-severity vulnerability in Linux kernel, published on 9 May 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/userptr: fix notifier vs folio deadlock
User is reporting what smells like notifier vs folio deadlock, where migrate_pages_batch() on core kernel side is holding folio lock(s) and then interacting with the mappings of it, however those mappings are tied to some userptr, which means calling into the notifier callback and grabbing the notifier lock. With perfect timing it looks possible that the pages we pulled from the hmm fault can get sniped by migrate_pages_batch() at the same time that we are holding the notifier lock to mark the pages as accessed/dirty, but at this point we also want to grab the folio locks(s) to mark them as dirty, but if they are contended from notifier/migrate_pages_batch side then we deadlock since folio lock won't be dropped until we drop the notifier lock.
Fortunately the mark_page_accessed/dirty is not really needed in the first place it seems and should have already been done by hmm fault, so just remove it.
(cherry picked from commit bd7c0cb695e87c0e43247be8196b4919edbe0e85)
Weakness: CWE-667
Which versions are affected by CVE-2025-37868?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-37868?
Apply the vendor's patch.
Is CVE-2025-37868 being exploited?
There is no known exploitation of CVE-2025-37868 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-37868, DEBIAN-CVE-2025-37868, GHSA-mfvr-qgfc-wvxq, UBUNTU-CVE-2025-37868.