Re: [BK PATCH] LSM changes for 2.5.59

From: Russell Coker (russellat_private)
Date: Tue Feb 11 2003 - 16:42:34 PST

  • Next message: Crispin Cowan: "Chris Wright's European Vacation"

    On Mon, 10 Feb 2003 23:38, LA Walsh wrote:
    > > And modularizing that logic
    > > has interesting implications; what happens to your applications when
    > > you turn off the kernel DAC logic and replace it with something
    > > arbitrary?
    >
    > ---
    > 	You tell me.  The idea is configurability: "truly generic".  It
    > depends on what policy you define.  I'm not about to guess
    > what would happen to "applications" (which?  Random?) that _you_ put on
    > your own system that has a security policy that _you_ define.
    
    I think that most people who want to use LSM and similar systems don't want to 
    re-write any significant portion of their applications.  People who want 
    serious security and are prepared to re-write applications will probably want 
    a high-assurance kernel and won't use Linux.
    
    A large number of applications depend on Unix permission checks.  Actions such 
    as treating a file as a configuration file if it lacks execute access 
    (accorting to stat(2)) but trying to execute it if it appears to have execute 
    access is reasonably common.
    
    Also many applications check the apparent permissions of files before trying 
    to access them, a file which doesn't appear to have read access may not even 
    be opened.
    
    I've been running a SE Linux play machine with all files mode 0777 for a few 
    weeks.  I've had to change the permissions on many files to get things 
    working basically for this reason, and I don't think that I've even addressed 
    half the problems this causes.  Even as an experiment this is too painful.  
    I'll re-format the machine soon...
    
    For all the machines I run (hand-held, laptop, embedded server, desktop, and 
    server) I plan to keep Unix permissions whether I need them or not.  Removing 
    them breaks too much compatability at the moment.  Maybe if someone else gets 
    a few thousand Linux machines running without any Unix permissions and fixes 
    a lot of the bugs I'll consider it.
    
    -- 
    http://www.coker.com.au/selinux/   My NSA Security Enhanced Linux packages
    http://www.coker.com.au/bonnie++/  Bonnie++ hard drive benchmark
    http://www.coker.com.au/postal/    Postal SMTP/POP benchmark
    http://www.coker.com.au/~russell/  My home page
    
    _______________________________________________
    linux-security-module mailing list
    linux-security-moduleat_private
    http://mail.wirex.com/mailman/listinfo/linux-security-module
    



    This archive was generated by hypermail 2b30 : Tue Feb 11 2003 - 16:43:25 PST