CVE-2026-68119

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> tcp: initialize standalone TCP-AO response padding<br /> <br /> tcp_v4_send_ack() and tcp_v6_send_response() construct standalone TCP<br /> responses with TCP-AO options. The option length carries the actual MAC<br /> length, but the TCP header length includes the option rounded up to a<br /> four-byte boundary.<br /> <br /> tcp_ao_hash_hdr() writes the MAC only. Thus, when the MAC length is not<br /> four-byte aligned, the one to three bytes after the MAC are left<br /> uninitialized and may be transmitted. For the normal TCP-AO hashing<br /> mode, those bytes also have to be initialized before computing the MAC.<br /> <br /> Initialize only the alignment padding in the TCP-AO branches, before<br /> hashing the header. Use TCPOPT_NOP, as in the normal TCP-AO output path.<br /> This avoids adding work to non-AO TCP responses while preserving a valid<br /> authenticated header.