On 03/01/02 20:55 +0900, chulmin wrote: > Hello, all. > > I know that only root account bind a port below 1024. > and anyuser except root can bind or use a port above 1024. > But named process uses udp port 53 with named uid. Named is started as root, which then binds to port 53, followed by dropping privileges to the specified user.
> How can it be possible? A process started as root can drop privileges, and provided that certain conditions are satisfied, regain them (IIRC). > and is it illegal or exception? Not illegal, uid 0 can become any user, but any uid cannot become uid 0 automatically. Devdas Bhagat
