LDM SegFault when loading additional plugins

[Mathieu Philippart]

By developing a plugin for LDM, I figured out that LDM load correctly up to 2 plugins, but when I try to load a third plugin, the program crashes with a Segmentation Fault.

Using Valgrind, I discovered that the problem came from the ldm_init_plugin function in ldmplugin.c. The plugin_names array is freed twice and there is a writing operation out of his memory allocation.

The attached patch fixes this problem.

[Alkis Georgopoulos (alkisg)]

Thank you for the patch; but keep in mind that LDM isn't developed anymore; the new LTSP19+ is using PAM-based logins, so normal DMs like gdm, lightdm etc.
https://github.com/ltsp/ltsp/tree/master/ltsp/client/login

Debian Buster and maybe Ubuntu 20.04 will probably be the last versions to ship LTSP5 with LDM.

[Alkis Georgopoulos (alkisg)]

Closing old LTSP bugs as they're no longer relevant after LTSP has been rewritten from scratch.