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    SubjectRe: [PATCH v2 5/5] selftests/ima: loading kernel modules
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    On Thu, 2019-02-28 at 23:32 +0100, Petr Vorel wrote:
    > Hi Mimi,
    >
    > > While the appended kernel module signature can be verified, when loading
    > > a kernel module via either the init_module or the finit_module syscall,
    > > verifying the IMA signature requires access to the file descriptor,
    > > which is only available via the finit_module syscall. As "modprobe"
    > > does not provide a flag allowing the syscall - init_module or
    > > finit_module - to be specified, this patch does not load a kernel
    > > module.
    >
    > > This test simply verifies that on secure boot enabled systems with
    > > "CONFIG_IMA_ARCH_POLICY" configured, that at least an appended kernel
    > > module signature or an IMA signature is required based on the Kconfig
    > > and the runtime IMA policy.
    >
    > > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
    > Reviewed-by: Petr Vorel <pvorel@suse.cz>
    >
    > ...
    > > diff --git a/tools/testing/selftests/ima/test_kernel_module.sh b/tools/testing/selftests/ima/test_kernel_module.sh
    > ...
    > > +# Are appended signatures required?
    > > +if [ -e /sys/module/module/parameters/sig_enforce ]; then
    > > + sig_enforce=$(cat /sys/module/module/parameters/sig_enforce)
    > > + if [ $sig_enforce = "Y" ]; then
    > > + log_pass "appended kernel module signature required"
    > > + fi
    > > +fi
    > Another possible helper [1]:
    > is_enabled() # or sysfs_enabled
    > {
    > [ -f "$1" ] && [ "$(cat $1)" = "Y" -o "$(cat $1)" = "1" ]
    > }
    >
    > is_enabled /sys/module/module/parameters/sig_enforce &&
    > log_pass "appended kernel module signature required"
    >

    Agreed.  As this is being used only here in the IMA selftests,
    deferring making this change until there is a generic common library.

    Mimi


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