CVE-2026-53016: crypto: ccp - copy IV using skcipher ivsize
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - copy IV using skcipher ivsize
AFALG rfc3686-ctr-aes-ccp requests pass an 8-byte IV to the driver.
ccpaescomplete() restores AESBLOCKSIZE bytes into the caller's IV buffer while RFC3686 skciphers expose an 8-byte IV, so the restore overruns the provided buffer.
Use cryptoskcipherivsize() to copy only the algorithm's IV length.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Compensating control
Update the Linux kernel to a version where the fix is applied: copy only the algorithm's IV length using crypto_skcipher_ivsize() instead of restoring AES_BLOCK_SIZE bytes into the caller's RFC3686 skcipher 8-byte IV buffer (fix described as "crypto: ccp - copy IV using skcipher ivsize").
Event History
Frequently Asked Questions
What conditions are required to trigger this issue?
The issue is triggered by AF_ALG rfc3686-ctr-aes-ccp requests. Those requests provide an 8-byte IV to the CCP driver, which previously restored AES_BLOCK_SIZE bytes into that caller-provided IV buffer.
What component is affected?
The affected component is the Linux kernel CCP crypto driver path handling AF_ALG RFC3686 CTR AES requests. The corrected behavior copies the IV using the skcipher algorithm's reported IV size rather than AES_BLOCK_SIZE.
What does the fix change?
The fix changes ccp_aes_complete() to use crypto_skcipher_ivsize() when copying the IV back to the caller. This limits the copy to the algorithm's IV length and prevents writing beyond the 8-byte RFC3686 IV buffer.