The ZFS_IOC_RECV_NEW ioctl, in the heal receive path, similarly truncated a 64-bit payload size to a 32-bit integer for allocation, then used the original 64-bit size as the length for a byteswap operation.
A local user with the "receive" delegated ZFS permission can trigger kernel memory corruption via ZFS_IOC_RECV_NEW by sending a crafted receive stream in heal mode.