Merge tag 'v6.18rc4-SMB-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull smb client fixes from Steve French:

 - Fix change notify packet validation check

 - Refcount fix (e.g. rename error paths)

 - Fix potential UAF due to missing locks on directory lease refcount

* tag 'v6.18rc4-SMB-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb: client: validate change notify buffer before copy
  smb: client: fix refcount leak in smb2_set_path_attr
  smb: client: fix potential UAF in smb2_close_cached_fid()

Author: torvalds

fs/smb/client/cached_dir.c

@@ -388,11 +388,11 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 			 * lease. Release one here, and the second below.
 			 */
 			cfid->has_lease = false;
-			kref_put(&cfid->refcount, smb2_close_cached_fid);
+			close_cached_dir(cfid);
 		}
 		spin_unlock(&cfids->cfid_list_lock);
 
-		kref_put(&cfid->refcount, smb2_close_cached_fid);
+		close_cached_dir(cfid);
 	} else {
 		*ret_cfid = cfid;
 		atomic_inc(&tcon->num_remote_opens);
@@ -438,12 +438,14 @@ int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
 
 static void
 smb2_close_cached_fid(struct kref *ref)
+__releases(&cfid->cfids->cfid_list_lock)
 {
 	struct cached_fid *cfid = container_of(ref, struct cached_fid,
 					       refcount);
 	int rc;
 
-	spin_lock(&cfid->cfids->cfid_list_lock);
+	lockdep_assert_held(&cfid->cfids->cfid_list_lock);
+
 	if (cfid->on_list) {
 		list_del(&cfid->entry);
 		cfid->on_list = false;
@@ -478,7 +480,7 @@ void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
 	spin_lock(&cfid->cfids->cfid_list_lock);
 	if (cfid->has_lease) {
 		cfid->has_lease = false;
-		kref_put(&cfid->refcount, smb2_close_cached_fid);
+		close_cached_dir(cfid);
 	}
 	spin_unlock(&cfid->cfids->cfid_list_lock);
 	close_cached_dir(cfid);
@@ -487,7 +489,7 @@ void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
 
 void close_cached_dir(struct cached_fid *cfid)
 {
-	kref_put(&cfid->refcount, smb2_close_cached_fid);
+	kref_put_lock(&cfid->refcount, smb2_close_cached_fid, &cfid->cfids->cfid_list_lock);
 }
 
 /*
@@ -596,7 +598,7 @@ cached_dir_offload_close(struct work_struct *work)
 
 	WARN_ON(cfid->on_list);
 
-	kref_put(&cfid->refcount, smb2_close_cached_fid);
+	close_cached_dir(cfid);
 	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cached_close);
 }
 
@@ -762,7 +764,7 @@ static void cfids_laundromat_worker(struct work_struct *work)
 			 * Drop the ref-count from above, either the lease-ref (if there
 			 * was one) or the extra one acquired.
 			 */
-			kref_put(&cfid->refcount, smb2_close_cached_fid);
+			close_cached_dir(cfid);
 	}
 	queue_delayed_work(cfid_put_wq, &cfids->laundromat_work,
 			   dir_cache_timeout * HZ);

fs/smb/client/smb2inode.c

@@ -1294,6 +1294,8 @@ static int smb2_set_path_attr(const unsigned int xid, struct cifs_tcon *tcon,
 	smb2_to_name = cifs_convert_path_to_utf16(to_name, cifs_sb);
 	if (smb2_to_name == NULL) {
 		rc = -ENOMEM;
+		if (cfile)
+			cifsFileInfo_put(cfile);
 		goto smb2_rename_path;
 	}
 	in_iov.iov_base = smb2_to_name;

fs/smb/client/smb2pdu.c

@@ -4054,9 +4054,12 @@ SMB2_change_notify(const unsigned int xid, struct cifs_tcon *tcon,
 
 		smb_rsp = (struct smb2_change_notify_rsp *)rsp_iov.iov_base;
 
-		smb2_validate_iov(le16_to_cpu(smb_rsp->OutputBufferOffset),
-				le32_to_cpu(smb_rsp->OutputBufferLength), &rsp_iov,
+		rc = smb2_validate_iov(le16_to_cpu(smb_rsp->OutputBufferOffset),
+				le32_to_cpu(smb_rsp->OutputBufferLength),
+				&rsp_iov,
 				sizeof(struct file_notify_information));
+		if (rc)
+			goto cnotify_exit;
 
 		*out_data = kmemdup((char *)smb_rsp + le16_to_cpu(smb_rsp->OutputBufferOffset),
 				le32_to_cpu(smb_rsp->OutputBufferLength), GFP_KERNEL);