1. 14 Apr, 2014 1 commit
    • Paul Moore's avatar
      selinux: correctly label /proc inodes in use before the policy is loaded · e6496f50
      Paul Moore authored
      commit f64410ec upstream.
      
      This patch is based on an earlier patch by Eric Paris, he describes
      the problem below:
      
        "If an inode is accessed before policy load it will get placed on a
         list of inodes to be initialized after policy load.  After policy
         load we call inode_doinit() which calls inode_doinit_with_dentry()
         on all inodes accessed before policy load.  In the case of inodes
         in procfs that means we'll end up at the bottom where it does:
      
           /* Default to the fs superblock SID. */
           isec->sid = sbsec->sid;
      
           if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
                   if (opt_dentry) {
                           isec->sclass = inode_mode_to_security_class(...)
                           rc = selinux_proc_get_sid(opt_dentry,
                                                     isec->sclass,
                                                     &sid);
                           if (rc)
                                   goto out_unlock;
                           isec->sid = sid;
                   }
           }
      
         Since opt_dentry is null, we'll never call selinux_proc_get_sid()
         and will leave the inode labeled with the label on the superblock.
         I believe a fix would be to mimic the behavior of xattrs.  Look
         for an alias of the inode.  If it can't be found, just leave the
         inode uninitialized (and pick it up later) if it can be found, we
         should be able to call selinux_proc_get_sid() ..."
      
      On a system exhibiting this problem, you will notice a lot of files in
      /proc with the generic "proc_t" type (at least the ones that were
      accessed early in the boot), for example:
      
         # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
         system_u:object_r:proc_t:s0 /proc/sys/kernel/shmmax
      
      However, with this patch in place we see the expected result:
      
         # ls -Z /proc/sys/kernel/shmmax | awk '{ print $4 " " $5 }'
         system_u:object_r:sysctl_kernel_t:s0 /proc/sys/kernel/shmmax
      
      Cc: Eric Paris <eparis@redhat.com>
      Signed-off-by: default avatarPaul Moore <pmoore@redhat.com>
      Acked-by: default avatarEric Paris <eparis@redhat.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e6496f50
  2. 03 Apr, 2014 23 commits
  3. 31 Mar, 2014 16 commits