[PATCH v4 23/24] integrity/powerpc: Improve error handling & reporting when loading certs

2023-01-20 Thread Andrew Donnellan
From: Russell Currey 

A few improvements to load_powerpc.c:

 - include integrity.h for the pr_fmt()
 - move all error reporting out of get_cert_list()
 - use ERR_PTR() to better preserve error detail
 - don't use pr_err() for missing keys

Signed-off-by: Russell Currey 
Signed-off-by: Andrew Donnellan 

---

v3: New patch
---
 .../integrity/platform_certs/load_powerpc.c   | 26 ++-
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/security/integrity/platform_certs/load_powerpc.c 
b/security/integrity/platform_certs/load_powerpc.c
index 1e4f80a4e71c..dee51606d5f4 100644
--- a/security/integrity/platform_certs/load_powerpc.c
+++ b/security/integrity/platform_certs/load_powerpc.c
@@ -14,9 +14,15 @@
 #include 
 #include 
 #include "keyring_handler.h"
+#include "../integrity.h"
 
 /*
  * Get a certificate list blob from the named secure variable.
+ *
+ * Returns:
+ *  - a pointer to a kmalloc'd buffer containing the cert list on success
+ *  - NULL if the key does not exist
+ *  - an ERR_PTR on error
  */
 static __init void *get_cert_list(u8 *key, unsigned long keylen, u64 *size)
 {
@@ -25,19 +31,19 @@ static __init void *get_cert_list(u8 *key, unsigned long 
keylen, u64 *size)
 
rc = secvar_ops->get(key, keylen, NULL, size);
if (rc) {
-   pr_err("Couldn't get size: %d\n", rc);
-   return NULL;
+   if (rc == -ENOENT)
+   return NULL;
+   return ERR_PTR(rc);
}
 
db = kmalloc(*size, GFP_KERNEL);
if (!db)
-   return NULL;
+   return ERR_PTR(-ENOMEM);
 
rc = secvar_ops->get(key, keylen, db, size);
if (rc) {
kfree(db);
-   pr_err("Error reading %s var: %d\n", key, rc);
-   return NULL;
+   return ERR_PTR(rc);
}
 
return db;
@@ -69,7 +75,11 @@ static int __init load_powerpc_certs(void)
 */
db = get_cert_list("db", 3, &dbsize);
if (!db) {
-   pr_err("Couldn't get db list from firmware\n");
+   pr_info("Couldn't get db list from firmware\n");
+   } else if (IS_ERR(db)) {
+   rc = PTR_ERR(db);
+   pr_err("Error reading db from firmware: %d\n", rc);
+   return rc;
} else {
rc = parse_efi_signature_list("powerpc:db", db, dbsize,
  get_handler_for_db);
@@ -81,6 +91,10 @@ static int __init load_powerpc_certs(void)
dbx = get_cert_list("dbx", 4,  &dbxsize);
if (!dbx) {
pr_info("Couldn't get dbx list from firmware\n");
+   } else if (IS_ERR(dbx)) {
+   rc = PTR_ERR(dbx);
+   pr_err("Error reading dbx from firmware: %d\n", rc);
+   return rc;
} else {
rc = parse_efi_signature_list("powerpc:dbx", dbx, dbxsize,
  get_handler_for_dbx);
-- 
2.39.0



Re: [PATCH v4 23/24] integrity/powerpc: Improve error handling & reporting when loading certs

2023-01-24 Thread Mimi Zohar
On Fri, 2023-01-20 at 18:43 +1100, Andrew Donnellan wrote:
> From: Russell Currey 
> 
> A few improvements to load_powerpc.c:
> 
>  - include integrity.h for the pr_fmt()
>  - move all error reporting out of get_cert_list()
>  - use ERR_PTR() to better preserve error detail
>  - don't use pr_err() for missing keys
> 
> Signed-off-by: Russell Currey 
> Signed-off-by: Andrew Donnellan 

Thanks,

Reviewed-by: Mimi Zohar