path: root/init
diff options
authorDavid Howells <dhowells@redhat.com>2019-08-19 17:17:40 -0700
committerJames Morris <jmorris@namei.org>2019-08-19 21:54:15 -0700
commit49fcf732bdae0550721ef73af7c45109ce26b2a9 (patch)
treecdf90d95cc5fb01413ac3c83f51796c1c3a0cdec /init
parent000d388ed3bbed745f366ce71b2bb7c2ee70f449 (diff)
lockdown: Enforce module signatures if the kernel is locked down
If the kernel is locked down, require that all modules have valid signatures that we can verify. I have adjusted the errors generated: (1) If there's no signature (ENODATA) or we can't check it (ENOPKG, ENOKEY), then: (a) If signatures are enforced then EKEYREJECTED is returned. (b) If there's no signature or we can't check it, but the kernel is locked down then EPERM is returned (this is then consistent with other lockdown cases). (2) If the signature is unparseable (EBADMSG, EINVAL), the signature fails the check (EKEYREJECTED) or a system error occurs (eg. ENOMEM), we return the error we got. Note that the X.509 code doesn't check for key expiry as the RTC might not be valid or might not have been transferred to the kernel's clock yet. [Modified by Matthew Garrett to remove the IMA integration. This will be replaced with integration with the IMA architecture policy patchset.] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <matthewgarrett@google.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Jessica Yu <jeyu@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'init')
1 files changed, 5 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index 0e2344389501..e6069368f278 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1939,6 +1939,11 @@ config MODULE_SIG
kernel build dependency so that the signing tool can use its crypto
+ You should enable this option if you wish to use either
+ CONFIG_SECURITY_LOCKDOWN_LSM or lockdown functionality imposed via
+ another LSM - otherwise unsigned modules will be loadable regardless
+ of the lockdown policy.
!!!WARNING!!! If you enable this option, you MUST make sure that the
module DOES NOT get stripped after being signed. This includes the
debuginfo strip done by some packagers (such as rpmbuild) and

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