encrypted-keys: check hex2bin result

For each hex2bin call in encrypted keys, check that the ascii hex string
is valid.  On failure, return -EINVAL.

Changelog v1:
- hex2bin now returns an int

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 3f577954b85a..f33804c1b4c8 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -667,11 +667,19 @@ static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
                 return -EINVAL;
 
         hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2;
-        hex2bin(epayload->iv, hex_encoded_iv, ivsize);
-        hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen);
+        ret = hex2bin(epayload->iv, hex_encoded_iv, ivsize);
+        if (ret < 0)
+                return -EINVAL;
+        ret = hex2bin(epayload->encrypted_data, hex_encoded_data,
+                      encrypted_datalen);
+        if (ret < 0)
+                return -EINVAL;
 
         hmac = epayload->format + epayload->datablob_len;
-        hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE);
+        ret = hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2),
+                      HASH_SIZE);
+        if (ret < 0)
+                return -EINVAL;
 
         mkey = request_master_key(epayload, &master_key, &master_keylen);
         if (IS_ERR(mkey))