[PATCH v2 4/4] integrity: prompt keyring name for unknown key request

[Bruno Meneguele <bmeneg@redhat.com>]

Depending on the IMA policy a key can be searched in multiple keyrings (e.g.
.ima and .platform) and possibly failing for both. However, for the user not
aware of the searching order it's not clear what's the keyring the kernel
didn't find the key. With this patch we improve this feedback by printing
the keyring "description" (name).

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
---
 security/integrity/digsig_asymmetric.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index cfa4127d0518..14de98ef67f6 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -55,8 +55,14 @@ static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
 	}
 
 	if (IS_ERR(key)) {
-		pr_err_ratelimited("Request for unknown key '%s' err %ld\n",
-				   name, PTR_ERR(key));
+		if (keyring)
+			pr_err_ratelimited("Request for unknown key '%s' in '%s' keyring. err %ld\n",
+					   name, keyring->description,
+					   PTR_ERR(key));
+		else
+			pr_err_ratelimited("Request for unknown key '%s' err %ld\n",
+					   name, PTR_ERR(key));
+
 		switch (PTR_ERR(key)) {
 			/* Hide some search errors */
 		case -EACCES:
-- 
2.26.2