Re: suid script

[Helge Hafting <helge.hafting@daldata.no>]

[...]
> the executable (bash, whatever) opens the file 
> it closes it
> it changes uid/gid to reflect suid status -> so it becames root or whatever
> it reopens it
> and executes it
> 
> problem: you can change the content of the file between the two !!
> so you can have your script, running as root, executing whatever you want !!

So that's the problem with SUID scripts.  Seems to me
it could be solved by *not* closing the script file, just keep it
open.  Why can't that be done?
It can't be possible, or someone would surely have fixed it
a long time ago?

Helge Hafting