Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull integrity updates from James Morris:
 "Mimi Zohar says:

   'Linux 5.0 introduced the platform keyring to allow verifying the IMA
    kexec kernel image signature using the pre-boot keys. This pull
    request similarly makes keys on the platform keyring accessible for
    verifying the PE kernel image signature.

    Also included in this pull request is a new IMA hook that tags tmp
    files, in policy, indicating the file hash needs to be calculated.
    The remaining patches are cleanup'"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  evm: Use defined constant for UUID representation
  ima: define ima_post_create_tmpfile() hook and add missing call
  evm: remove set but not used variable 'xattr'
  encrypted-keys: fix Opt_err/Opt_error = -1
  kexec, KEYS: Make use of platform keyring for signature verify
  integrity, KEYS: add a reference to platform keyring

1 files changed, 22 insertions, 1 deletions

diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 81728717523d..c05c29ae4d5d 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -24,6 +24,9 @@ static struct key *builtin_trusted_keys;
 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
 static struct key *secondary_trusted_keys;
 #endif
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+static struct key *platform_trusted_keys;
+#endif
 
 extern __initconst const u8 system_certificate_list[];
 extern __initconst const unsigned long system_certificate_list_size;
@@ -237,11 +240,22 @@ int verify_pkcs7_signature(const void *data, size_t len,
 #else
 		trusted_keys = builtin_trusted_keys;
 #endif
+	} else if (trusted_keys == VERIFY_USE_PLATFORM_KEYRING) {
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+		trusted_keys = platform_trusted_keys;
+#else
+		trusted_keys = NULL;
+#endif
+		if (!trusted_keys) {
+			ret = -ENOKEY;
+			pr_devel("PKCS#7 platform keyring is not available\n");
+			goto error;
+		}
 	}
 	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
 	if (ret < 0) {
 		if (ret == -ENOKEY)
-			pr_err("PKCS#7 signature not signed with a trusted key\n");
+			pr_devel("PKCS#7 signature not signed with a trusted key\n");
 		goto error;
 	}
 
@@ -266,3 +280,10 @@ error:
 EXPORT_SYMBOL_GPL(verify_pkcs7_signature);
 
 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
+
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+void __init set_platform_trusted_keys(struct key *keyring)
+{
+	platform_trusted_keys = keyring;
+}
+#endif