/ is writable on mac... leading to lots of awkward msi droppings?

[Charles Davis]

On 1/5/11 1:18 AM, Charles Davis wrote:
> On 1/5/11 12:31 AM, Dan Kegel wrote:
>> Quentin Paris informs me that the root directory is
>> user-writable on MacOSX (shudder), which means
>> our beloved z: mapping leads to lots of garbage
>> directories named e.g. /fd91216cc2ce81eb2ce16a058619
>> after running msi installers.
> Now where would he get that idea from?
> 
> chips-computer:~ chip$ uname # show that this is Darwin (Mac OS X)
> Darwin
> chips-computer:~ chip$ ls -ld / # show permissions of root directory
> drwxr-xr-x  39 root  admin  1394 Nov 15 09:00 /
> chips-computer:~ chip$ mkdir /a # try to create something in /
> mkdir: /a: Permission denied
> 
> At least on my Mac, only root gets to write to /.
Huh. That's funny. I checked my other Mac (my second one), and its root
directory was group-writable by group 'admin' (the System
Administrators' group):

chip at chips-computer-3 ~ $ ls -ld /
drwxrwxr-t 40 root admin 1428 Nov 18 08:43 /

Maybe I changed it on the first one. Oh well.

Unfortunately, most Macs happen to be single-user systems where the user
belongs to the 'admin' group. (Otherwise, it would be impossible to
become root at all, especially since the root account is completely
disabled.) That should explain what Quentin observed about writing to /.
Personally, I think everyone should just 'sudo chmod g-w /'. But that's
just me. Most Mac users don't even know what 'Terminal' is, let alone
understand the purpose of the magic incantation I just recited.

But why is MSI putting anything in Z:\ at all? I'm guessing those
folders really belong in the temp directory; if the temp dir is Z:\,
then we really need to fix that. No program should be using the root
directory as a dumping ground :).

On both my Macs, TEMP and TMP are set to the Temp directory in my Wine
home directory, so I really wouldn't understand why MSI is dumping stuff
in Z:\.

Chip