On Tue, 2023-01-31 at 22:02 -0500, Mimi Zohar wrote:
> Hi Roberto,
>
> > +check_mmap() {
> > + local hook="$1"
> > + local arg="$2"
> > + local test_file fowner rule result test_file_entry
> > +
> > + echo -e "\nTest: ${FUNCNAME[0]} (hook=\"$hook\", test_mmap arg: \"$arg\")"
> > +
> > + if ! test_file=$(mktemp -p "$PWD"); then
> > + echo "${RED}Cannot write $test_file${NORM}"
> > + return "$HARDFAIL"
> > + fi
> > +
> > + fowner="$MMAP_CHECK_FOWNER"
> > + rule="$MEASURE_MMAP_CHECK_RULE"
> > +
> > + if [ "$hook" = "MMAP_CHECK_REQPROT" ]; then
> > + fowner="$MMAP_CHECK_REQPROT_FOWNER"
> > + rule="$MEASURE_MMAP_CHECK_REQPROT_RULE"
> > + fi
> > +
> > + if ! chown "$fowner" "$test_file"; then
> > + echo "${RED}Cannot change owner of $test_file${NORM}"
> > + return "$HARDFAIL"
> > + fi
> > +
> > + check_load_ima_rule "$rule"
> > + result=$?
> > + if [ $result -ne "$OK" ]; then
> > + return $result
> > + fi
> > +
> > + test_mmap "$test_file" "$arg"
> > +
> > + if [ "$TFAIL" != "yes" ]; then
> > + echo -n "Result (expect found): "
> > + else
> > + echo -n "Result (expect not found): "
> > + fi
> > +
> > + test_file_entry=$(awk '$5 == "'"$test_file"'"' < /sys/kernel/security/ima/ascii_runtime_measurements)
> > + if [ -z "$test_file_entry" ]; then
> > + echo "not found"
> > + return "$FAIL"
> > + fi
>
> Using temporary files should prevent having multiple records. Having a
> verbose option to show the actual matching measurement list record
> would be nice.
>
> > +
> > + echo "found"
> > + return "$OK"
> > +}
> > +
>
>
> > +
> > +# Run in the new environment if TST_ENV is set.
> > +_run_env "$TST_KERNEL" "$PWD/$(basename "$0")" "TST_ENV=$TST_ENV TST_KERNEL=$TST_KERNEL PATH=$PATH LD_LIBRARY_PATH=$LD_LIBRARY_PATH VERBOSE=$VERBOSE"
> > +
> > +# Exit from the creator of the new environment.
> > +_exit_env "$TST_KERNEL"
> > +
> > +# Mount filesystems in the new environment.
> > +_init_env
> > +
> > +if [ "$(whoami)" != "root" ]; then
> > + echo "${CYAN}This script must be executed as root${NORM}"
> > + exit "$SKIP"
> > +fi
> > +
> > +if [ ! -f /sys/kernel/security/ima/policy ]; then
> > + echo "${CYAN}IMA policy file not found${NORM}"
> > + exit "$SKIP"
> > +fi
> > +
> > +if ! cat /sys/kernel/security/ima/policy &> /dev/null; then
> > + echo "${CYAN}IMA policy file is not readable${NORM}"
> > + exit "$SKIP"
> > +fi
>
> An existing policy with an mmap rule would affect this test. Check to
> see if one already exists.
Not sure about this. We are specifying the filesystem UUID and the file
owner. Should be enough to avoid interferences. Also
check_load_ima_rule() avoids duplicated rules.
Roberto
> > +
> > +if [ -n "$TST_KEY_PATH" ]; then
> > + if [ "${TST_KEY_PATH:0:1}" != "/" ]; then
> > + echo "${RED}Absolute path required for the signing key${NORM}"
> > + exit "$FAIL"
> > + fi
> >
