fs/smbfs/request.c: fix NULL dereference

@@ -783,20 +783,23 @@ int smb_request_recv(struct smb_sb_info 
 			break;
 		break;
 
 		/* We should never be called with any of these states */
 	case SMB_RECV_END:
 	case SMB_RECV_REQUEST:
 		server->rstate = SMB_RECV_END;
 		break;
 	}
 
+	if (!req)
+		return -ENOMEM;
+
 	if (result < 0) {
 		/* We saw an error */
 		return result;
 	}
 
 	if (server->rstate != SMB_RECV_END)
 		return 0;
 
 	result = 0;
 	if (req->rq_trans2_command && req->rq_rcls == SUCCESS)

@@ -564,152 +564,8 @@ out:
 	return result;
 }
 
 /*
- * Receive a transaction2 response
- * Return: 0 if the response has been fully read
- *         1 if there are further "fragments" to read
- *        <0 if there is an error
- */
-static int smb_recv_trans2(struct smb_sb_info *server, struct smb_request *req)
-{
-	unsigned char *inbuf;
-	unsigned int parm_disp, parm_offset, parm_count, parm_tot;
-	unsigned int data_disp, data_offset, data_count, data_tot;
-	int hdrlen = SMB_HEADER_LEN + req->rq_resp_wct*2 - 2;
-
-	VERBOSE("handling trans2\n");
-
-	inbuf = req->rq_header;
-	data_tot    = WVAL(inbuf, smb_tdrcnt);
-	parm_tot    = WVAL(inbuf, smb_tprcnt);
-	parm_disp   = WVAL(inbuf, smb_prdisp);
-	parm_offset = WVAL(inbuf, smb_proff);
-	parm_count  = WVAL(inbuf, smb_prcnt);
-	data_disp   = WVAL(inbuf, smb_drdisp);
-	data_offset = WVAL(inbuf, smb_droff);
-	data_count  = WVAL(inbuf, smb_drcnt);
-
-	/* Modify offset for the split header/buffer we use */
-	if (data_count || data_offset) {
-		if (unlikely(data_offset < hdrlen))
-			goto out_bad_data;
-		else
-			data_offset -= hdrlen;
-	}
-	if (parm_count || parm_offset) {
-		if (unlikely(parm_offset < hdrlen))
-			goto out_bad_parm;
-		else
-			parm_offset -= hdrlen;
-	}
-
-	if (parm_count == parm_tot && data_count == data_tot) {
-		/*
-		 * This packet has all the trans2 data.
-		 *
-		 * We setup the request so that this will be the common
-		 * case. It may be a server error to not return a
-		 * response that fits.
-		 */
-		VERBOSE("single trans2 response  "
-			"dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
-			data_count, parm_count,
-			data_offset, parm_offset);
-		req->rq_ldata = data_count;
-		req->rq_lparm = parm_count;
-		req->rq_data = req->rq_buffer + data_offset;
-		req->rq_parm = req->rq_buffer + parm_offset;
-		if (unlikely(parm_offset + parm_count > req->rq_rlen))
-			goto out_bad_parm;
-		if (unlikely(data_offset + data_count > req->rq_rlen))
-			goto out_bad_data;
-		return 0;
-	}
-
-	VERBOSE("multi trans2 response  "
-		"frag=%d, dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
-		req->rq_fragment,
-		data_count, parm_count,
-		data_offset, parm_offset);
-
-	if (!req->rq_fragment) {
-		int buf_len;
-
-		/* We got the first trans2 fragment */
-		req->rq_fragment = 1;
-		req->rq_total_data = data_tot;
-		req->rq_total_parm = parm_tot;
-		req->rq_ldata = 0;
-		req->rq_lparm = 0;
-
-		buf_len = data_tot + parm_tot;
-		if (buf_len > SMB_MAX_PACKET_SIZE)
-			goto out_too_long;
-
-		req->rq_trans2bufsize = buf_len;
-		req->rq_trans2buffer = smb_kmalloc(buf_len, GFP_NOFS);
-		if (!req->rq_trans2buffer)
-			goto out_no_mem;
-		memset(req->rq_trans2buffer, 0, buf_len);
-
-		req->rq_parm = req->rq_trans2buffer;
-		req->rq_data = req->rq_trans2buffer + parm_tot;
-	} else if (unlikely(req->rq_total_data < data_tot ||
-			    req->rq_total_parm < parm_tot))
-		goto out_data_grew;
-
-	if (unlikely(parm_disp + parm_count > req->rq_total_parm ||
-		     parm_offset + parm_count > req->rq_rlen))
-		goto out_bad_parm;
-	if (unlikely(data_disp + data_count > req->rq_total_data ||
-		     data_offset + data_count > req->rq_rlen))
-		goto out_bad_data;
-
-	inbuf = req->rq_buffer;
-	memcpy(req->rq_parm + parm_disp, inbuf + parm_offset, parm_count);
-	memcpy(req->rq_data + data_disp, inbuf + data_offset, data_count);
-
-	req->rq_ldata += data_count;
-	req->rq_lparm += parm_count;
-
-	/*
-	 * Check whether we've received all of the data. Note that
-	 * we use the packet totals -- total lengths might shrink!
-	 */
-	if (req->rq_ldata >= data_tot && req->rq_lparm >= parm_tot) {
-		req->rq_ldata = data_tot;
-		req->rq_lparm = parm_tot;
-		return 0;
-	}
-	return 1;
-
-out_too_long:
-	printk(KERN_ERR "smb_trans2: data/param too long, data=%u, parm=%u\n",
-		data_tot, parm_tot);
-	goto out_EIO;
-out_no_mem:
-	printk(KERN_ERR "smb_trans2: couldn't allocate data area of %d bytes\n",
-	       req->rq_trans2bufsize);
-	req->rq_errno = -ENOMEM;
-	goto out;
-out_data_grew:
-	printk(KERN_ERR "smb_trans2: data/params grew!\n");
-	goto out_EIO;
-out_bad_parm:
-	printk(KERN_ERR "smb_trans2: invalid parms, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
-	       parm_disp, parm_count, parm_tot, parm_offset);
-	goto out_EIO;
-out_bad_data:
-	printk(KERN_ERR "smb_trans2: invalid data, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
-	       data_disp, data_count, data_tot, data_offset);
-out_EIO:
-	req->rq_errno = -EIO;
-out:
-	return req->rq_errno;
-}
-
-/*
  * State machine for receiving responses. We handle the fact that we can't
  * read the full response in one try by having states telling us how much we
  * have read.
  *

@@ -785,39 +641,14 @@ int smb_request_recv(struct smb_sb_info 
 
 		/* We should never be called with any of these states */
 	case SMB_RECV_END:
 	case SMB_RECV_REQUEST:
-		server->rstate = SMB_RECV_END;
-		break;
+		BUG();
 	}
 
 	if (result < 0) {
 		/* We saw an error */
 		return result;
 	}
 
-	if (server->rstate != SMB_RECV_END)
-		return 0;
-
-	result = 0;
-	if (req->rq_trans2_command && req->rq_rcls == SUCCESS)
-		result = smb_recv_trans2(server, req);
-
-	/*
-	 * Response completely read. Drop any extra bytes sent by the server.
-	 * (Yes, servers sometimes add extra bytes to responses)
-	 */
-	VERBOSE("smb_len: %d   smb_read: %d\n",
-		server->smb_len, server->smb_read);
-	if (server->smb_read < server->smb_len)
-		smb_receive_drop(server);
-
-	server->rstate = SMB_RECV_START;
-
-	if (!result) {
-		list_del_init(&req->rq_queue);
-		req->rq_flags |= SMB_REQ_RECEIVED;
-		smb_rput(req);
-		wake_up_interruptible(&req->rq_wait);
-	}
 	return 0;
 }

@@ -786,8 +642,7 @@ int smb_request_recv(struct smb_sb_info 
 		/* We should never be called with any of these states */
 	case SMB_RECV_END:
 	case SMB_RECV_REQUEST:
-		server->rstate = SMB_RECV_END;
-		break;
+		BUG();
 	}
 
 	if (result < 0) {