fs/ntfs3: Fix invalid free in log_replay

log_read_rst() returns ENOMEM error when there is not enough memory.
In this case, if info is returned without initialization,
it attempts to kfree the uninitialized info->r_page pointer. This patch
moves the memset initialization code to before log_read_rst() is called.
Reported-by: Gerald Lee <sundaywind2004@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/fslog.c

@@ -1185,8 +1185,6 @@ static int log_read_rst(struct ntfs_log *log, u32 l_size, bool first,
 	if (!r_page)
 		return -ENOMEM;
 
-	memset(info, 0, sizeof(struct restart_info));
-
 	/* Determine which restart area we are looking for. */
 	if (first) {
 		vbo = 0;
@@ -3791,10 +3789,11 @@ int log_replay(struct ntfs_inode *ni, bool *initialized)
 	if (!log)
 		return -ENOMEM;
 
+	memset(&rst_info, 0, sizeof(struct restart_info));
+
 	log->ni = ni;
 	log->l_size = l_size;
 	log->one_page_buf = kmalloc(page_size, GFP_NOFS);
-
 	if (!log->one_page_buf) {
 		err = -ENOMEM;
 		goto out;
@@ -3842,6 +3841,7 @@ int log_replay(struct ntfs_inode *ni, bool *initialized)
 	if (rst_info.vbo)
 		goto check_restart_area;
 
+	memset(&rst_info2, 0, sizeof(struct restart_info));
 	err = log_read_rst(log, l_size, false, &rst_info2);
 
 	/* Determine which restart area to use. */