Re: Linux 2.2.18pre21

Matthias Andree
2000-11-17T12:04:24Z

On Thu, 16 Nov 2000, H. Peter Anvin wrote:

> BUG: you *MUST* chdir() into the chroot jail before it does you any
> good at all!
>
> I usually recommend:

#include <sysexits.h>
/* for EX_NOUSER */

> mkdir("foo");
> chdir("foo");
> chroot(".");

add this:

/* DO REPLACE 500 BY AN EXISTING USER ID */
/* DO NOT REPLACE IT BY 0! */
/* DO NOT USE OTHER FUNCTIONS THAN setuid() */
if(setuid(500)) { _exit(EX_NOUSER); }

(For the records and search engines, most people should know that, but
to have it all in one mail.)