CVE-2026-93243

/// Technical description

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

mm/secretmem: properly account locked pages

secretmem accounts folios by treating memory as if it were mlock()'d and

thus limited by the RLIMIT_MEMLOCK limit.

However the folios are unevictable and remain so until the inode is

evicted, eliminating usual mlock() semantics - mapping folios then

unmapping them does not clear their unevictable state, since it depends on

AS_UNEVICTABLE, not PG_mlocked.

A user can therefore easily work around the RLIMIT_MEMLOCK limit - simply

map then unmap and VmLck no longer counts the secretmem range. Worse,

folios are not accounted in the process's RSS, meaning the OOM killer

won't know to kill the process.

Repeatedly mapping/unmapping (or forking) can then result in the

consumption of all available system memory with unevictable folios and

cause system instability.

A secretmem fd can be passed between processes and over fork so a

per-process limit simply does not make sense, so f

/// 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