kppp crash as user not as root

spoody_goon · 12-04-2006, 10:07 AM

I've read many posts and tried the suggestions but I must be missing something. I can use kppp to connect to the internet as root but not as user. As user I get:

Code:

Opener: received SetSecret
Opener: received OpenLock

Opener: received OpenDevice
Opener: received ExecPPPDaemon
segmentation fault

And then it crashed like it was killed

I am using:
-Slackware 11
-Kernel 2.6.18
-KDE
-and martain_modem for a modem driver

I am willing to try anything suggested even if I have already tried it.

Thank you.

osvaldomarques · 12-05-2006, 02:02 PM

Hi spoody_goon,

First you need to identify where is the kppp program with the command

Code:

which kppp

It will display the directory where kppp is installed, for example, /usr/lib/kde3/bin/kppp; then enter the command

Code:

ls -l /usr/lib/kde3/bin/kppp

It will display the attributes of the file

Code:

-rwsr-xr-x  1 root root 543096 2005-07-25 10:50 /usr/lib/kde3/bin/kppp

If the first permission letters aren't "rws" or the user/group are not root as shown on the above display, this is your problem; In this case, as root enter the commands

Code:

chown root.root /usr/lib/kde3/bin/kppp
chmod u+s /usr/lib/kde3/kppp

Remember to replace the "/usr/lib/kde3" by the directory you found on the first command in this post.

The kppp must be setuid; it must always run as root.

spoody_goon · 12-05-2006, 02:15 PM

Thank you, I have followed your instructions. kppp was set to -rwsr-xr-x but I executed chown and chmod anyway just to be sure.

I may be wrong but if the permissions was wrong I don't think I would be able to execute kppp at all instead of just having it crash, when it initializes the modem?

Do you have any other suggestions?

Again Thanks

osvaldomarques · 12-05-2006, 02:39 PM

Repeat the same commands for pppd. It also has to run as root and must be setuid. The problem may be on it. The segmentation fault can occur on such case if it is not conveniently attended; for example, if you try to open a file that you have not permission, you will give a NULL pointer to it; if you check this pointer before use it, you may display a message like "file xyz could not be opened". However, if you assume that you always will open that file with no problems, on the first read you will have a segmentation fault.

As an example, this c source file will show you:

Code:

#include "stdio.h"

int main(void)
{
  FILE *fs = NULL
      ;

  char txt[16]
      ;
  while (fgets(txt, sizeof(txt), fs))
  {
    break;
  }
}

Save this file as xyz.c, compile it with the following command

Code:

gcc -o xyz xyz.c

and run it with

Code:

./xyz