ksmbd: fix uninitialized pointer read in smb2_create_link()

[ Upstream commit df14afe ]

There is a case that file_present is true and path is uninitialized.
This patch change file_present is set to false by default and set to
true when patch is initialized.

Fixes: 74d7970 ("ksmbd: fix racy issue from using ->d_parent and ->d_name")
Reported-by: Coverity Scan <scan-admin@coverity.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/smb/server/smb2pdu.c

@@ -5559,7 +5559,7 @@ static int smb2_create_link(struct ksmbd_work *work,
 {
 	char *link_name = NULL, *target_name = NULL, *pathname = NULL;
 	struct path path;
-	bool file_present = true;
+	bool file_present = false;
 	int rc;
 
 	if (buf_len < (u64)sizeof(struct smb2_file_link_info) +
@@ -5592,8 +5592,8 @@ static int smb2_create_link(struct ksmbd_work *work,
 	if (rc) {
 		if (rc != -ENOENT)
 			goto out;
-		file_present = false;
-	}
+	} else
+		file_present = true;
 
 	if (file_info->ReplaceIfExists) {
 		if (file_present) {