VBoxLinuxAdditions.run --target is dangerous if dir exists (possible data loss)

[Hagge]

Running VBoxLinuxAdditions.run usually creates a directory in /tmp. But running this script with option --target <dir> is very dangerous, if the directory <dir> already exists. This may result in a possible large data loss! The script more or less does:

1. mkdir <dir>
2. [extract several files to <dir>]
3. chown -R <currentuser>:<currentuser> <dir>
4. [build and install drivers]
5. rm -rf <dir>

Now imagine you call this with the home directory as argument.

sudo ./VBoxLinuxAdditions.run --target ~

1. This is a no-op, the home directory already exists.
2. This will extract files all across the home directory. Bad idea!
3. This will transfer ownership of *all* files in user's home directory (including the directory itself) to root. Very bad idea!!!
4. [not relevant]
5. This will remove the whole home directory. Totally unacceptable!!!

This is a grossly negligent, even fatal script design!!!!

If you want to do it this way, then there *must* be a check if the target directory <dir> already exists and the script must fail with an error if so.