CVE-2022-50731

/// Technical description

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

crypto: akcipher - default implementation for setting a private key

Changes from v1:

* removed the default implementation from set_pub_key: it is assumed that

an implementation must always have this callback defined as there are

no use case for an algorithm, which doesn't need a public key

Many akcipher implementations (like ECDSA) support only signature

verifications, so they don't have all callbacks defined.

Commit 78a0324f4a53 ("crypto: akcipher - default implementations for

request callbacks") introduced default callbacks for sign/verify

operations, which just return an error code.

However, these are not enough, because before calling sign the caller would

likely call set_priv_key first on the instantiated transform (as the

in-kernel testmgr does). This function does not have a default stub, so the

kernel crashes, when trying to set a private key on an akcipher, which

doesn't support signature genera

/// 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