High [CVE-2026-53016] ccp - copy IV using skcipher ivsize

In the Linux kernel, the following vulnerability has been resolved: crypto: ccp - copy IV using skcipher ivsize AF_ALG rfc3686-ctr-aes-ccp requests pass an 8-byte IV to the driver. ccp_aes_complete() restores AES_BLOCK_SIZE bytes into the caller's IV buffer while RFC3686 skciphers expose an 8-byte IV, so the restore overruns the provided buffer.

Use crypto_skcipher_ivsize() to copy only the algorithm's IV length. When processing AF_ALG rfc3686-ctr-aes-ccp requests, the ccp_aes_complete() function attempts to restore more data than the allocated buffer for the Initialization Vector (IV) can hold.

This leads to a buffer overrun, which can result in memory corruption within the kernel. An out-of-bounds write exists in the AMD CCP AES completion path because ccp_aes_complete() restores AES_BLOCK_SIZE bytes into req iv even when the selected skcipher exposes a shorter IV.

For the CVSS the PR:L is used because a local user or local process can reach AF_ALG crypto interfaces without needing full administrator privileges when the vulnerable CCP backed algorithm is available. The issue is not network reachable and requires local code execution on a system with the affected CCP crypto driver and algorithm available.

Red Hat severity: Moderate — CVSS 7 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H). Weakness: CWE-805.