CVE-2025-38595: linux kernel vulnerability

What is known

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.

Business impact

Successful exploitation of CVE-2025-38595, a high vulnerability (CVSS 7.8) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
• Reference
• Reference
• Reference
• Reference