1 files changed, 11 insertions, 3 deletions

diff --git a/crypto/authenc.c b/crypto/authenc.c
index 37f54d1b2f66..4be293a4b5f0 100644
--- a/crypto/authenc.c
+++ b/crypto/authenc.c
@@ -58,14 +58,22 @@ int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key,
                 return -EINVAL;
         if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM)
                 return -EINVAL;
-        if (RTA_PAYLOAD(rta) < sizeof(*param))
+
+        /*
+         * RTA_OK() didn't align the rtattr's payload when validating that it
+         * fits in the buffer.  Yet, the keys should start on the next 4-byte
+         * aligned boundary.  To avoid confusion, require that the rtattr
+         * payload be exactly the param struct, which has a 4-byte aligned size.
+         */
+        if (RTA_PAYLOAD(rta) != sizeof(*param))
                 return -EINVAL;
+        BUILD_BUG_ON(sizeof(*param) % RTA_ALIGNTO);
 
         param = RTA_DATA(rta);
         keys->enckeylen = be32_to_cpu(param->enckeylen);
 
-        key += RTA_ALIGN(rta->rta_len);
-        keylen -= RTA_ALIGN(rta->rta_len);
+        key += rta->rta_len;
+        keylen -= rta->rta_len;
 
         if (keylen < keys->enckeylen)
                 return -EINVAL;