[PATCH linux-next] ecryptfs: main: use strscpy() to instead of strncpy()

[yang.yang29]

From: Xu Panda <xu.panda@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Yang Yang <yang.yang29@xxxxxxx>
---
 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