CVE-2026-68125

Technical Description

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

mac802154: llsec: reject frames shorter than the authentication tag

llsec_do_decrypt_auth() computes the associated-data length for the

AEAD request as

assoclen += datalen - authlen;

where datalen is the number of bytes after the MAC header and authlen

(4, 8 or 16) is the length of the authentication tag. Nothing verifies

that the frame actually carries at least authlen payload bytes. A

secured frame whose payload is shorter than the tag makes

datalen - authlen negative; assoclen is then passed to

aead_request_set_ad() as an unsigned value close to 4 GiB, so

crypto_aead_decrypt() walks far off the end of the scatterlist that

only spans the real frame.

The frame is fully attacker-controlled and reaches this path from any

IEEE 802.15.4 peer in radio range. Reject frames whose payload is

shorter than the authentication tag before the subtraction.

Dynamically reproduced on a KASAN kernel as a general-protection-faul

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