[Kde-games-devel] Re: KHighscore on multiple user systems

[Nicolas Hadacek]

On Monday 12 May 2003 11:16 am, Oswald Buddenhagen wrote:
> On Mon, May 12, 2003 at 12:14:23PM -0400, George Staikos wrote:
> >   Dropping the gid gains you nothing because any buffer overflow
> >   anywhere in the game will allow the user to regain the gid.
>
> yep, and it's the exactly same feature nicolas' code relied upon ... so
> either way "my" solution is better, as he admitted.

> one more person to point to kdebase/kdm/backend/dm.c:StorePid() :)

yeah that proved handy... is this really working for NFS ?

Here is my next (and hopefully final) try: see the attached patch and the 
KFileLock class (useful in kdelibs ??).

now at program start, I am just opening a file descriptor on the system-wide 
highscore file and then immediately and definitely dropping the effective 
group id with "setregid" (if I understood correctly the man page). An exploit 
can then only give you access to the game highscore file. Hopefully not a big 
deal :)

See you,
Nicolas
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