ksmbd: do not grant v2 lease if parent lease key and epoch are not set

commit 691aae4f upstream.

This patch fix xfstests generic/070 test with smb2 leases = yes.

cifs.ko doesn't set parent lease key and epoch in create context v2 lease.
ksmbd suppose that parent lease and epoch are vaild if data length is
v2 lease context size and handle directory lease using this values.
ksmbd should hanle it as v1 lease not v2 lease if parent lease key and
epoch are not set in create context v2 lease.

Cc: stable@vger.kernel.org
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/smb/server/oplock.c

@@ -1208,7 +1208,9 @@ int smb_grant_oplock(struct ksmbd_work *work, int req_op_level, u64 pid,
 
 	/* Only v2 leases handle the directory */
 	if (S_ISDIR(file_inode(fp->filp)->i_mode)) {
-		if (!lctx || lctx->version != 2)
+		if (!lctx || lctx->version != 2 ||
+		    (lctx->flags != SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE &&
+		     !lctx->epoch))
 			return 0;
 	}
 
@@ -1470,8 +1472,9 @@ void create_lease_buf(u8 *rbuf, struct lease *lease)
 		buf->lcontext.LeaseFlags = lease->flags;
 		buf->lcontext.Epoch = cpu_to_le16(lease->epoch);
 		buf->lcontext.LeaseState = lease->state;
-		memcpy(buf->lcontext.ParentLeaseKey, lease->parent_lease_key,
-		       SMB2_LEASE_KEY_SIZE);
+		if (lease->flags == SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE)
+			memcpy(buf->lcontext.ParentLeaseKey, lease->parent_lease_key,
+			       SMB2_LEASE_KEY_SIZE);
 		buf->ccontext.DataOffset = cpu_to_le16(offsetof
 				(struct create_lease_v2, lcontext));
 		buf->ccontext.DataLength = cpu_to_le32(sizeof(struct lease_context_v2));
@@ -1536,8 +1539,9 @@ struct lease_ctx_info *parse_lease_state(void *open_req, bool is_dir)
 		lreq->flags = lc->lcontext.LeaseFlags;
 		lreq->epoch = lc->lcontext.Epoch;
 		lreq->duration = lc->lcontext.LeaseDuration;
-		memcpy(lreq->parent_lease_key, lc->lcontext.ParentLeaseKey,
-				SMB2_LEASE_KEY_SIZE);
+		if (lreq->flags == SMB2_LEASE_FLAG_PARENT_LEASE_KEY_SET_LE)
+			memcpy(lreq->parent_lease_key, lc->lcontext.ParentLeaseKey,
+			       SMB2_LEASE_KEY_SIZE);
 		lreq->version = 2;
 	} else {
 		struct create_lease *lc = (struct create_lease *)cc;