CVE-2026-72103

Technical Description

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

dm: avoid leaking the caller's thread keyring via the table device file

The refactoring in commit a28d893eb327 ("md: port block device access to file")

accidentally causes the caller's thread keyring to be kept alive long

beyond the caller's lifetime.

As a result, "cryptsetup luksSuspend" silently fails to wipe the

LUKS volume key from memory.

In detail: "cryptsetup luksOpen" uses its supposedly ephemeral thread

keyring to pass the volume key to the kernel. dm-crypt's

crypt_set_keyring_key() copies the key material into its own

crypt_config structure and then drops its own reference to the key in

the keyring with key_put().

With this fix, restoring pre-v6.9 behavior, the copy in the thread

keyring is then promptly garbage collected, such that exactly one copy

of the volume key remains. This single copy is correctly wiped from

memory on "cryptsetup luksSuspend".

Without this fix, the thread keyring and the volume

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