passt/test/valgrind.supp

# tcp_sock_consume() calls recv() with MSG_TRUNC and no buffer to discard data
{
   passt_recv_MSG_TRUNC_into_NULL_buffer
   Memcheck:Param
   socketcall.recvfrom(buf)
   ...
   fun:tcp_sock_consume
}

# same as above, for architectures with the recv() system call (at least i686):
{
   passt_recv_MSG_TRUNC_into_NULL_buffer
   Memcheck:Param
   socketcall.recv(buf)
   ...
   fun:tcp_sock_consume
}