[PATCH 6.6 001/105] smb: client: Fix refcount leak for cifs_sb_tlink

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Shuhao Fu <sfual@cse.ust.hk>

commit c2b77f42205ef485a647f62082c442c1cd69d3fc upstream.

Fix three refcount inconsistency issues related to `cifs_sb_tlink`.

Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be
called after successful calls to `cifs_sb_tlink()`. Three calls fail to
update refcount accordingly, leading to possible resource leaks.

Fixes: 8ceb98437946 ("CIFS: Move rename to ops struct")
Fixes: 2f1afe25997f ("cifs: Use smb 2 - 3 and cifsacl mount options getacl functions")
Fixes: 366ed846df60 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function")
Cc: stable@vger.kernel.org
Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/smb/client/inode.c   |    6 ++++--
 fs/smb/client/smb2ops.c |    8 ++++----
 2 files changed, 8 insertions(+), 6 deletions(-)

--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -2319,8 +2319,10 @@ cifs_do_rename(const unsigned int xid, s
 	tcon = tlink_tcon(tlink);
 	server = tcon->ses->server;
 
-	if (!server->ops->rename)
-		return -ENOSYS;
+	if (!server->ops->rename) {
+		rc = -ENOSYS;
+		goto do_rename_exit;
+	}
 
 	/* try path-based rename first */
 	rc = server->ops->rename(xid, tcon, from_dentry,
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -3072,8 +3072,7 @@ get_smb2_acl_by_path(struct cifs_sb_info
 	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
 	if (!utf16_path) {
 		rc = -ENOMEM;
-		free_xid(xid);
-		return ERR_PTR(rc);
+		goto put_tlink;
 	}
 
 	oparms = (struct cifs_open_parms) {
@@ -3105,6 +3104,7 @@ get_smb2_acl_by_path(struct cifs_sb_info
 		SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 	}
 
+put_tlink:
 	cifs_put_tlink(tlink);
 	free_xid(xid);
 
@@ -3145,8 +3145,7 @@ set_smb2_acl(struct smb_ntsd *pnntsd, __
 	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
 	if (!utf16_path) {
 		rc = -ENOMEM;
-		free_xid(xid);
-		return rc;
+		goto put_tlink;
 	}
 
 	oparms = (struct cifs_open_parms) {
@@ -3167,6 +3166,7 @@ set_smb2_acl(struct smb_ntsd *pnntsd, __
 		SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 	}
 
+put_tlink:
 	cifs_put_tlink(tlink);
 	free_xid(xid);
 	return rc;