3 ms·

chroot is a different, older system that pre-dates different mount namespaces.

• dredmorbius 2y ago
  My understanding is that chroot presently does make use of the different mount namespaces, though I could be wrong here. How did chroot used to work in this regard? Were mountpoints outside the chroot jail itself accessible? Because if so, that ... would violate some key points of using a chroot jail in the first place. Though if chroot applied strictly to the filesystem and not mount points that might still offer benefits, and I seem to recall running into ... unexpected behaviours ... using chroots in the past.
  • LegionMammal978 2y ago
    When you create a new mount namespace, the kernel creates a copy of every mount reachable from the filesystem (as visible to the process creating it). Then, it changes the current process's root directory and current directory to point to the same paths in the corresponding mounts. Changing a process's root via chroot is otherwise a totally separate operation.
  • caf 2y ago
    The classic chroot(2) system call just changes the directory entry that's used for the root in that process. It only affects pathname resolution (including resolution of the pathnames in symbolic links). If an unconstrained uid zero process is inside the chroot but can access or create device nodes, it can mount devices within the chroot just fine.