Improper Input Validation
A flaw was found in the crypto subsystem of the Linux kernel before version kernel-4.15-rc4. The "null skcipher" was being dropped when each af_alg_ctx was freed instead of when the aead_tfm was freed. This can cause the null skcipher to be freed while it is still in use leading to a local user being able to crash the system or possibly escalate privileges.
CWE-20 - Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.