Running programs under root with suid bit

[Richard_Xeli]

Hello,

i've got a minimal test case with a C program with the following code

#include <stdio.h>

int main(){
printf("uid = %d", getuid());
printf("euid = %d", geteuid());
}

After compiling the program and running it i get my own user id (1000), so thats fine.

Then i want to run it under root.

I do chown root.root <program name> and chmod 4771 <program name>

after running it again it still shows me 1000 as it's uid.

Trying stuff like loading modules also does not work, so it really does not have root.

Am i missing something here?

Any help would be greatly appreciated.

Ps.

I'm running debian lenny, executing the exact same commands on the ping executable does give me the correct results...

[Rubberman]

Well, you have remove read permission from "others" (including yourself) which is one thing, and you haven't properly set the setuid bit(s).

First, set the proper permissions: chmod 755 cmdname
Then, set the setuid bit(s): chmod +s cmdname

Try that and see what happens.

[Richard_Xeli]

Hello,

Thank you for your reply,

Sorry i have not been able to reply earlier, i've found the solution the partition was mounted with the nosuid flag, which makes using the suid bit kind of hard

Richard