integrity: Only use machine keyring when uefi_check_trust_mok_keys is true

With the introduction of uefi_check_trust_mok_keys, it signifies the end-
user wants to trust the machine keyring as trusted keys.  If they have
chosen to trust the machine keyring, load the qualifying keys into it
during boot, then link it to the secondary keyring .  If the user has not
chosen to trust the machine keyring, it will be empty and not linked to
the secondary keyring.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 7b719aa761885fa370f381a737076026bfe54274..c8c8a4a4e7a00c800f10ab939839ca00bf378691 100644 (file)
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -112,7 +112,7 @@ static int __init __integrity_init_keyring(const unsigned int id,
        } else {
                if (id == INTEGRITY_KEYRING_PLATFORM)
                        set_platform_trusted_keys(keyring[id]);
-               if (id == INTEGRITY_KEYRING_MACHINE)
+               if (id == INTEGRITY_KEYRING_MACHINE && trust_moklist())
                        set_machine_trusted_keys(keyring[id]);
                if (id == INTEGRITY_KEYRING_IMA)
                        load_module_cert(keyring[id]);

diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 730771eececd7ba00a5ea3f9cecfd4a4107e6748..2e214c76115869ac2f0d576f609b3e12a68075c6 100644 (file)
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -287,9 +287,14 @@ static inline void __init add_to_platform_keyring(const char *source,
 
 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
 void __init add_to_machine_keyring(const char *source, const void *data, size_t len);
+bool __init trust_moklist(void);
 #else
 static inline void __init add_to_machine_keyring(const char *source,
                                                  const void *data, size_t len)
 {
 }
+static inline bool __init trust_moklist(void)
+{
+       return false;
+}
 #endif

diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c
index 4872850d081fe4d635a87cea579ed7df8afbfe0c..1db4d3b4356dc4d32cd373fceb0bbfc8fb3271c7 100644 (file)
--- a/security/integrity/platform_certs/keyring_handler.c
+++ b/security/integrity/platform_certs/keyring_handler.c
@@ -83,7 +83,7 @@ __init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
 __init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type)
 {
        if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) {
-               if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING))
+               if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && trust_moklist())
                        return add_to_machine_keyring;
                else
                        return add_to_platform_keyring;

diff --git a/security/integrity/platform_certs/machine_keyring.c b/security/integrity/platform_certs/machine_keyring.c
index 09fd8f20c756075d2cdd94ba4628e8c227b5f4c2..7aaed7950b6e3673fdb734ea1b13fa3db516cf76 100644 (file)
--- a/security/integrity/platform_certs/machine_keyring.c
+++ b/security/integrity/platform_certs/machine_keyring.c
@@ -8,6 +8,8 @@
 #include <linux/efi.h>
 #include "../integrity.h"
 
+static bool trust_mok;
+
 static __init int machine_keyring_init(void)
 {
        int rc;
@@ -59,3 +61,17 @@ static __init bool uefi_check_trust_mok_keys(void)
 
        return false;
 }
+
+bool __init trust_moklist(void)
+{
+       static bool initialized;
+
+       if (!initialized) {
+               initialized = true;
+
+               if (uefi_check_trust_mok_keys())
+                       trust_mok = true;
+       }
+
+       return trust_mok;
+}