I create a user, and the attributes are created correctly:

objectclass: systemQuotas
objectclass: posixAccount
objectclass: inetOrgPerson
objectclass: organizationalPerson
objectclass: person
quota: /home,500,510,0,0

Configuration of /etc/pam.d/common-session:
# here are the per-package modules (the "Primary" block)
session [default=1] pam_permit.so
# here's the fallback if no module succeeds
session requisite pam_deny.so
# prime the stack with a positive return value if there isn't one already;
# this avoids us returning an error just because nothing sets a success code
# since the modules above will each just jump around
session required pam_permit.so
# and here are more per-package modules (the "Additional" block)
session required pam_unix.so
session [success=ok default=ignore] pam_ldap.so minimum_uid=1000
session optional pam_systemd.so
session optional pam_mkhomedir.so skel=/etc/skel umask=077
session required pam_setquota.so
# end of pam-auth-update config

When logging in with an LDAP user, the following appears in Debian logs: pam_setquota(login:session): no limits defined in configuration for user zprieto on /dev/vda5. I don’t know what is missing that prevents the user’s attributes from being read. Thank you very much.