From 9ba6324ca9c4a1f4fc24c3620ae41fc10239a4cf Mon Sep 17 00:00:00 2001
From: Zhihao Cheng <chengzhihao1@huawei.com>
Date: Tue, 29 Sep 2020 20:45:30 +0800
Subject: [PATCH] ubifs: Don't parse authentication mount options in remount
 process

commit bb674a4d4de1032837fcbf860a63939e66f0b7ad upstream.

There is no need to dump authentication options while remounting,
because authentication initialization can only be doing once in
the first mount process. Dumping authentication mount options in
remount process may cause memory leak if UBIFS has already been
mounted with old authentication mount options.

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Cc: <stable@vger.kernel.org>  # 4.20+
Fixes: d8a22773a12c6d7 ("ubifs: Enable authentication support")
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/ubifs/super.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 05ce40ee7d64d..94ddb0ff1ad7d 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1092,14 +1092,20 @@ static int ubifs_parse_options(struct ubifs_info *c, char *options,
 			break;
 		}
 		case Opt_auth_key:
-			c->auth_key_name = kstrdup(args[0].from, GFP_KERNEL);
-			if (!c->auth_key_name)
-				return -ENOMEM;
+			if (!is_remount) {
+				c->auth_key_name = kstrdup(args[0].from,
+								GFP_KERNEL);
+				if (!c->auth_key_name)
+					return -ENOMEM;
+			}
 			break;
 		case Opt_auth_hash_name:
-			c->auth_hash_name = kstrdup(args[0].from, GFP_KERNEL);
-			if (!c->auth_hash_name)
-				return -ENOMEM;
+			if (!is_remount) {
+				c->auth_hash_name = kstrdup(args[0].from,
+								GFP_KERNEL);
+				if (!c->auth_hash_name)
+					return -ENOMEM;
+			}
 			break;
 		case Opt_ignore:
 			break;