smb: fix invalid username check in smb3_fs_context_parse_param()

[ Upstream commit ed66121 ]

Since the maximum return value of strnlen(..., CIFS_MAX_USERNAME_LEN)
is CIFS_MAX_USERNAME_LEN, length check in smb3_fs_context_parse_param()
is always FALSE and invalid.

Fix the comparison in if statement.

Signed-off-by: Yiqi Sun <sunyiqixm@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: sunichi

fs/smb/client/fs_context.c

@@ -1472,7 +1472,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 			break;
 		}
 
-		if (strnlen(param->string, CIFS_MAX_USERNAME_LEN) >
+		if (strnlen(param->string, CIFS_MAX_USERNAME_LEN) ==
 		    CIFS_MAX_USERNAME_LEN) {
 			pr_warn("username too long\n");
 			goto cifs_parse_mount_err;