CVE-2026-53373

/// Technical description

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

mm/vma: do not try to unmap a VMA if mmap_prepare() invoked from mmap()

The mmap_prepare hook functionality includes the ability to invoke

mmap_prepare() from the mmap() hook of existing 'stacked' drivers, that is

ones which are capable of calling the mmap hooks of other drivers/file

systems (e.g. overlayfs, shm).

As part of the mmap_prepare action functionality, we deal with errors by

unmapping the VMA should one arise. This works in the usual mmap_prepare

case, as we invoke this action at the last moment, when the VMA is

established in the maple tree.

However, the mmap() hook passes a not-fully-established VMA pointer to the

caller (which is the motivation behind the mmap_prepare() work), which is

detached.

So attempting to unmap a VMA in this state will be problematic, with the

most obvious symptom being a warning in vma_mark_detached(), because the

VMA is already detached.

It's also unncessary - the mmap()

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References