[PATCH v4 7/9] crash_dump: Check the function return codes in restore_dm_crypt_keys_to_thread_keyring

[Coiby Xu <coiby.xu@gmail.com>]

We should check the return codes so we can abort if keyring allocation
or reading old memory fails.

Note there is no need to refer a key add_key_to_keyring, so delete
related code.

Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Coiby Xu <coiby.xu@gmail.com>
---
 kernel/crash_dump_dm_crypt.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/kernel/crash_dump_dm_crypt.c b/kernel/crash_dump_dm_crypt.c
index e82693df73fb..b7629174e4db 100644
--- a/kernel/crash_dump_dm_crypt.c
+++ b/kernel/crash_dump_dm_crypt.c
@@ -66,7 +66,7 @@ static int add_key_to_keyring(struct dm_crypt_key *dm_key,
 			      key_ref_t keyring_ref)
 {
 	key_ref_t key_ref;
-	int r;
+	int r = 0;
 
 	/* create or update the requested key and add it to the target keyring */
 	key_ref = key_create_or_update(keyring_ref, "user", dm_key->key_desc,
@@ -74,8 +74,6 @@ static int add_key_to_keyring(struct dm_crypt_key *dm_key,
 				       KEY_USR_ALL, KEY_ALLOC_IN_QUOTA);
 
 	if (!IS_ERR(key_ref)) {
-		r = key_ref_to_ptr(key_ref)->serial;
-		key_ref_put(key_ref);
 		pr_debug("Success adding key %s\n", dm_key->key_desc);
 	} else {
 		r = PTR_ERR(key_ref);
@@ -134,9 +132,14 @@ static int restore_dm_crypt_keys_to_thread_keyring(void)
 	}
 
 	addr = dm_crypt_keys_addr;
-	dm_crypt_keys_read((char *)&key_count, sizeof(key_count), &addr);
+	ret = dm_crypt_keys_read((char *)&key_count, sizeof(key_count), &addr);
+	if (ret < 0) {
+		pr_err("Failed to read the number of dm-crypt keys\n");
+		goto out;
+	}
+
 	if (key_count > KEY_NUM_MAX) {
-		pr_warn("Failed to read the number of dm-crypt keys\n");
+		pr_warn("Read %u dm-crypt keys (max=%u)\n", key_count, KEY_NUM_MAX);
 		ret = -1;
 		goto out;
 	}
@@ -151,12 +154,18 @@ static int restore_dm_crypt_keys_to_thread_keyring(void)
 		goto out;
 	}
 
-	dm_crypt_keys_read((char *)keys_header, keys_header_size, &addr);
+	ret = dm_crypt_keys_read((char *)keys_header, keys_header_size, &addr);
+	if (ret < 0) {
+		pr_err("Failed to read dm-crypt keys\n");
+		goto out;
+	}
 
 	for (int i = 0; i < keys_header->total_keys; i++) {
 		key = &keys_header->keys[i];
 		pr_debug("Get key (size=%u)\n", key->key_size);
-		add_key_to_keyring(key, keyring_ref);
+		ret = add_key_to_keyring(key, keyring_ref);
+		if (ret)
+			break;
 	}
 
 out:
-- 
2.55.0