CVE-2026-10643 Out-of-bounds heap write in Zephyr `recvmsg()` ancillary-data path (`insert_pktinfo` undersizes the control-buffer capacity check)

Zephyr's IP socket recvmsg implementation subsys/net/lib/sockets/socketsinet.c, insertpktinfo validated the user-supplied ancillary msgcontrol buffer using only the payload length msg-msgcontrollen pktinfolen before writing a full control message consisting of an aligned cmsg header plus the...