diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 51651314b7a6..b9cdafb98e45 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -19,6 +19,7 @@
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include "ecryptfs_kernel.h"
+#include <keys/user-type.h>
 
 /*
  * request_key returned an error instead of a valid key address;
@@ -738,6 +739,20 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
 		goto out_free_unlock;
 	}
 
+	struct user_key_payload *ukp = user_key_payload_locked(auth_tok_key);
+		if (!ukp || ukp->datalen < sizeof(struct ecryptfs_auth_tok)) {
+			printk(KERN_ERR "Error key payload too small\n");
+			rc = -EINVAL;
+			goto out_free_unlock;
+		}
+
+	if (s->auth_tok->token.password.session_key_encryption_key_bytes >
+			sizeof(s->auth_tok->token.password.session_key_encryption_key)) {
+		printk(KERN_ERR "Error FNEK key size too large\n");
+		rc = -EINVAL;
+		goto out_free_unlock;
+	}
+
 	md5(s->auth_tok->token.password.session_key_encryption_key,
 	    s->auth_tok->token.password.session_key_encryption_key_bytes,
 	    s->hash);