CVE-2025-38595 xen: fix UAF in dmabuf_exp_from_pages()
A use-after-free vulnerability in the Linux kernel's Xen driver allows local attackers to execute arbitrary code or escalate privileges.
- 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-2025-38595?
CVE-2025-38595 is a high-severity use after free vulnerability in Linux kernel, published on 19 Aug 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:
xen: fix UAF in dmabuf_exp_from_pages()
[dma_buf_fd() fixes; no preferences regarding the tree it goes through - up to xen folks]
As soon as we'd inserted a file reference into descriptor table, another thread could close it. That's fine for the case when all we are doing is returning that descriptor to userland (it's a race, but it's a userland race and there's nothing the kernel can do about it). However, if we follow fd_install() with any kind of access to objects that would be destroyed on close (be it the struct file itself or anything destroyed by its ->release()), we have a UAF.
dma_buf_fd() is a combination of reserving a descriptor and fd_install(). gntdev dmabuf_exp_from_pages() calls it and then proceeds to access the objects destroyed on close - starting with gntdev_dmabuf itself.
Fix that by doing reserving descriptor before anything else and do fd_install() only when everything had been set up.
Weakness: CWE-416
Which versions are affected by CVE-2025-38595?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38595?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-38595 being exploited?
There is no known exploitation of CVE-2025-38595 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-38595, DEBIAN-CVE-2025-38595, GHSA-43g4-4j68-8xj3, ROOT-OS-DEBIAN-11-CVE-2025-38595, ROOT-OS-DEBIAN-12-CVE-2025-38595, ROOT-OS-DEBIAN-13-CVE-2025-38595 and 3 more.