These commands list /dev entries which are writable by
find /dev -gid 0 -perm -20 -type c
find /dev -gid 0 -perm -20 -type b
I suspect they are errors. They are a security concern because they
could well make leaks of group root equivalent to full root access; e.g.
/dev/agpgart would be the first candidate alphabetically :)
In general, I would expect the following rules to apply:
- A /dev entry should only be writable by the group if it has a special
group (e.g. disk), or it is publicly writable.
The same argument applies to group root having read permissions as well
as write permissions.
Generalising further, these rules do not just apply to /dev, but also
much all other files or directories. I suggest a quick audit; it is just a
A number of these are set this way by convention (carried over when the dev
package was overhauled). Some of these are redundant because of pam_console,
others we'll have to look at more closely.
This defect is considered MUST-FIX for Florence Gold release
This should all be cleaned up as of dev-3.1.0-1, which is quite a bit more
careful about group ownerships and group read/write permissions. If this breaks
anything, I trust we'll find out in time to relax some of the restrictions or
fix some broken programs.