Stephen Smalley <[EMAIL PROTECTED]> writes: > > Hmmm...turns out to not be quite enough, as the /proc/sys inodes aren't > truly private to the fs, so we can run into them in a variety of > security hooks beyond just the inode hooks, such as > security_file_permission (when reading and writing them via the vfs > helpers), security_sb_mount (when mounting other filesystems on > directories in proc like binfmt_misc), and deeper within the security > module itself (as in flush_unauthorized_files upon inheritance across > execve). So I think we have to add an IS_PRIVATE() guard within > SELinux, as below. Note however that the use of the private flag here > could be confusing, as these inodes are _not_ private to the fs, are > exposed to userspace, and security modules must implement the sysctl > hook to get any access control over them.
Agreed, the naming is confusing, and using private here doesn't quite feel right. A practical question is: Will we ever encounter these inodes in the inode_init() path from superblock_init? If all of the accesses that we care about go through inode_doinit_with_dentry we can just walk the dcache to get the names, and that should work for the normal proc case as well. A somewhat related question: How do you handle security labels for sysfs? No fine grained security yet. If it doesn't look easy to solve this another way I will certainly go with marking the inodes private. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
