newgidmap

NOM

newgidmap - set the gid mapping of a user namespace

SYNOPSIS

newgidmap pid gid lowergid count [gid lowergid count [ ... ]]

The newgidmap sets /proc/[pid]/gid_map based on its command line arguments and the gids allowed. Subgid delegation can either be managed via /etc/subgid or through the configured NSS subid module. These options are mutually exclusive.

Note that the root group is not exempted from the requirement for a valid /etc/subgid entry.

After the pid argument, newgidmap expects sets of 3 integers:

gid

Beginning of the range of GIDs inside the user namespace.

lowergid

Beginning of the range of GIDs outside the user namespace.

count

Length of the ranges (both inside and outside the user namespace).

newgidmap verifies that the caller is the owner of the process indicated by pid and that for each of the above sets, each of the GIDs in the range [lowergid, lowergid+count) is allowed to the caller according to /etc/subgid before setting /proc/[pid]/gid_map.

Note that newgidmap may be used only once for a given process.