When runc is bind-mounting a particular path "with options", it has to
do so by first creating a bind-mount and the modifying the options of
said bind-mount via remount. However, in a user namespace, there are
restrictions on which flags you can change with a remount (due to
CL_UNPRIVILEGED being set in this instance). Docker historically has
ignored this, and as a result, internal Docker mounts (such as secrets)
haven't worked with --userns-remap. Fix this by preserving
CL_UNPRIVILEGED mount flags when Docker is spawning containers with user
namespaces enabled.
Ref: https://github.com/opencontainers/runc/pull/1603
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Upstream-commit: c0f883fdeeb2480970fb48fbcbc2a842aa5a90e8
Component: engine
77fe26d1a3