A vulnerability in the Linux kernel's calipso_skbuff_setattr() function mishandles large TCP payload lengths in IPv6 packets with CALIPSO options. This causes incorrect payload_len values when packets exceed the IPV6_MAXPLEN limit, potentially affecting network packet processing components such as nf_tables, conntrack, and sch_cake. The issue has been fixed by correctly setting payload_len based on the actual skb length, ensuring proper handling of large TCP packets with CALIPSO labels.