FAILED: patch "[PATCH] dm crypt: rewrite (wipe) key in crypto layer using random" failed to apply to 4.9-stable tree

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Ondrej Kozina <[email protected]>
Date: Mon, 24 Apr 2017 14:21:53 +0200
Subject: [PATCH] dm crypt: rewrite (wipe) key in crypto layer using random
data

The message "key wipe" used to wipe real key stored in crypto layer by rewriting it with zeroes. Since commit 28856a9 ("crypto: xts - consolidate sanity check for keys") this no longer works in FIPS mode for XTS.

While running in FIPS mode the crypto key part has to differ from the tweak key.

index 8bff6f7a4c6c..bb2e747907b0 100644
@@ -2152,12 +2152,16 @@ static int crypt_set_key(struct crypt_config *cc, char *key)
 
 static int crypt_wipe_key(struct crypt_config *cc)
 {
+	int r;
+
 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
-	memset(&cc->key, 0, cc->key_size * sizeof(u8));
+	get_random_bytes(&cc->key, cc->key_size);
 	kzfree(cc->key_string);
 	cc->key_string = NULL;
+	r = crypt_setkey(cc);
+	memset(&cc->key, 0, cc->key_size * sizeof(u8));
 
-	return crypt_setkey(cc);
+	return r;
 }
 
 static void crypt_dtr(struct dm_target *ti)