diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 5414253d4c9..259525c9abb 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -1303,6 +1303,13 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
 	}
 	(*new_auth_tok)->session_key.encrypted_key_size =
 		(body_size - (ECRYPTFS_SALT_SIZE + 5));
+	if ((*new_auth_tok)->session_key.encrypted_key_size
+	    > ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES) {
+		printk(KERN_WARNING "Tag 3 packet contains key larger "
+		       "than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES\n");
+		rc = -EINVAL;
+		goto out_free;
+	}
 	if (unlikely(data[(*packet_size)++] != 0x04)) {
 		printk(KERN_WARNING "Unknown version number [%d]\n",
 		       data[(*packet_size) - 1]);