CVE-2022-49899

/// Technical description

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

fscrypt: stop using keyrings subsystem for fscrypt_master_key

The approach of fs/crypto/ internally managing the fscrypt_master_key

structs as the payloads of "struct key" objects contained in a

"struct key" keyring has outlived its usefulness. The original idea was

to simplify the code by reusing code from the keyrings subsystem.

However, several issues have arisen that can't easily be resolved:

- When a master key struct is destroyed, blk_crypto_evict_key() must be

called on any per-mode keys embedded in it. (This started being the

case when inline encryption support was added.) Yet, the keyrings

subsystem can arbitrarily delay the destruction of keys, even past the

time the filesystem was unmounted. Therefore, currently there is no

easy way to call blk_crypto_evict_key() when a master key is

destroyed. Currently, this is worked around by holding an extra

reference to the filesystem's request_qu

/// 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