Linux From Scratch - Version r12.2-776-multilib

Chapter 7. Entering Chroot and Building Additional Temporary Tools

7.2. Changing Ownership

[Note]

Note

The commands in the remainder of this book must be performed while logged in as user root and no longer as user lfs. Also, double check that $LFS is set in root's environment.

Currently, the whole directory hierarchy in $LFS is owned by the user lfs, a user that exists only on the host system. If the directories and files under $LFS are kept as they are, they will be owned by a user ID without a corresponding account. This is dangerous because a user account created later could get this same user ID and would own all the files under $LFS, thus exposing these files to possible malicious manipulation.

To address this issue, change the ownership of the $LFS/* directories to user root by running the following command: 

chown --from lfs -R root:root $LFS/{usr,lib,var,etc,bin,sbin,tools}
case $(uname -m) in
  x86_64) chown --from lfs -R root:root $LFS/lib64 ;;
esac

Some more directories exists for multilib support. Change their ownership, too: 

chown -R root:root $LFS/lib32
chown -R root:root $LFS/libx32