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Date:   Wed, 28 Dec 2022 09:38:27 +0800 (CST)
Message-ID: <202212280938279799834@zte.com.cn>
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From:   <yang.yang29@zte.com.cn>
To:     <code@tyhicks.com>
Cc:     <viro@zeniv.linux.org.uk>, <brauner@kernel.org>,
        <ecryptfs@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <xu.panda@zte.com.cn>, <yang.yang29@zte.com.cn>
Subject: =?UTF-8?B?W1BBVENIIGxpbnV4LW5leHRdIGVjcnlwdGZzOiBtYWluOiB1c2Ugc3Ryc2NweSgpIHRvIGluc3RlYWQgb2Ygc3RybmNweSgp?=
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From: Xu Panda <xu.panda@zte.com.cn>

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.

Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
---
 fs/ecryptfs/main.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 2dc927ba067f..007bed5ddf6e 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -296,9 +296,8 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 			cipher_name_dst =
 				mount_crypt_stat->
 				global_default_cipher_name;
-			strncpy(cipher_name_dst, cipher_name_src,
-				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
-			cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+			strscpy(cipher_name_dst, cipher_name_src,
+				ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1);
 			cipher_name_set = 1;
 			break;
 		case ecryptfs_opt_ecryptfs_key_bytes:
@@ -328,9 +327,7 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 			fnek_src = args[0].from;
 			fnek_dst =
 				mount_crypt_stat->global_default_fnek_sig;
-			strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
-			mount_crypt_stat->global_default_fnek_sig[
-				ECRYPTFS_SIG_SIZE_HEX] = '\0';
+			strscpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX + 1);
 			rc = ecryptfs_add_global_auth_tok(
 				mount_crypt_stat,
 				mount_crypt_stat->global_default_fnek_sig,
@@ -350,10 +347,8 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 			fn_cipher_name_src = args[0].from;
 			fn_cipher_name_dst =
 				mount_crypt_stat->global_default_fn_cipher_name;
-			strncpy(fn_cipher_name_dst, fn_cipher_name_src,
-				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
-			mount_crypt_stat->global_default_fn_cipher_name[
-				ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+			strscpy(fn_cipher_name_dst, fn_cipher_name_src,
+				ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1);
 			fn_cipher_name_set = 1;
 			break;
 		case ecryptfs_opt_fn_cipher_key_bytes:
-- 
2.15.2