grub: load_env
16.3.42 load_env
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-- Command: load_env [--file file] [--skip-sig]
[whitelisted_variable_name] ...
Load all variables from the environment block file into the
environment. ⇒Environment block.
The '--file' option overrides the default location of the
environment block.
The '--skip-sig' option skips signature checking even when the
value of environment variable 'check_signatures' is set to
'enforce' (⇒check_signatures).
If one or more variable names are provided as arguments, they are
interpreted as a whitelist of variables to load from the
environment block file. Variables set in the file but not present
in the whitelist are ignored.
The '--skip-sig' option should be used with care, and should always
be used in concert with a whitelist of acceptable variables whose
values should be set. Failure to employ a carefully constructed
whitelist could result in reading a malicious value into critical
environment variables from the file, such as setting
'check_signatures=no', modifying 'prefix' to boot from an
unexpected location or not at all, etc.
When used with care, '--skip-sig' and the whitelist enable an
administrator to configure a system to boot only signed
configurations, but to allow the user to select from among multiple
configurations, and to enable "one-shot" boot attempts and
"savedefault" behavior. ⇒Using digital signatures, for more
information.