[PATCH 4/4] module, KEYS: Make use of platform keyring for signature verification

[Michal Suchanek <msuchanek@suse.de>]

Commit 278311e417be ("kexec, KEYS: Make use of platform keyring for signature verify")
adds support for use of platform keyring in kexec verification but
support for modules is missing.

Add support for verification of modules with keys from platform keyring
as well.

Fixes: 219a3e8676f3 ("integrity, KEYS: add a reference to platform keyring")
Cc: linux-modules@vger.kernel.org
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
 kernel/module_signing.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/kernel/module_signing.c b/kernel/module_signing.c
index 8723ae70ea1f..5e1624294874 100644
--- a/kernel/module_signing.c
+++ b/kernel/module_signing.c
@@ -38,8 +38,14 @@ int mod_verify_sig(const void *mod, struct load_info *info)
 	modlen -= sig_len + sizeof(ms);
 	info->len = modlen;
 
-	return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len,
-				      VERIFY_USE_SECONDARY_KEYRING,
-				      VERIFYING_MODULE_SIGNATURE,
-				      NULL, NULL);
+	ret = verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len,
+				     VERIFY_USE_SECONDARY_KEYRING,
+				     VERIFYING_MODULE_SIGNATURE,
+				     NULL, NULL);
+	if (ret == -ENOKEY && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
+		ret = verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len,
+					     VERIFY_USE_PLATFORM_KEYRING,
+					     VERIFYING_MODULE_SIGNATURE,
+					     NULL, NULL);
+	return ret;
 }
-- 
2.31.1