This patch adds support for checking environment variable's names.
Although TOMOYO already provides ability to check argv[]/envp[] passed to
execve() requests,
file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="bar"
will reject execution of /bin/sh if environment variable LD_LIBRARY_PATH is not
defined. To grant execution of /bin/sh if LD_LIBRARY_PATH is not defined,
administrators have to specify like
file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="/system/lib"
file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]=NULL
. Since there are many environment variables whereas conditional checks are
applied as "&&", it is difficult to cover all combinations. Therefore, this
patch supports conditional checks that are applied as "||", by specifying like
file execute /bin/sh
misc env LD_LIBRARY_PATH exec.envp["LD_LIBRARY_PATH"]="/system/lib"
which means "grant execution of /bin/sh if environment variable is not defined
or is defined and its value is /system/lib".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
