mei: bus: use sizeof of variable instead of struct type

There is a possibility of bug when variable type has changed but
corresponding struct passed to the sizeof has not.

Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20200723145927.882743-4-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/bus-fixup.c

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright (c) 2013-2019, Intel Corporation. All rights reserved.
+ * Copyright (c) 2013-2020, Intel Corporation. All rights reserved.
  * Intel Management Engine Interface (Intel MEI) Linux driver
  */
 
@@ -159,17 +159,17 @@ static int mei_osver(struct mei_cl_device *cldev)
 static int mei_fwver(struct mei_cl_device *cldev)
 {
 	char buf[MKHI_FWVER_BUF_LEN];
-	struct mkhi_msg *req;
+	struct mkhi_msg req;
+	struct mkhi_msg *rsp;
 	struct mkhi_fw_ver *fwver;
 	int bytes_recv, ret, i;
 
 	memset(buf, 0, sizeof(buf));
 
-	req = (struct mkhi_msg *)buf;
-	req->hdr.group_id = MKHI_GEN_GROUP_ID;
-	req->hdr.command = MKHI_GEN_GET_FW_VERSION_CMD;
+	req.hdr.group_id = MKHI_GEN_GROUP_ID;
+	req.hdr.command = MKHI_GEN_GET_FW_VERSION_CMD;
 
-	ret = __mei_cl_send(cldev->cl, buf, sizeof(struct mkhi_msg_hdr),
+	ret = __mei_cl_send(cldev->cl, (u8 *)&req, sizeof(req),
 			    MEI_CL_IO_TX_BLOCKING);
 	if (ret < 0) {
 		dev_err(&cldev->dev, "Could not send ReqFWVersion cmd\n");
@@ -188,7 +188,8 @@ static int mei_fwver(struct mei_cl_device *cldev)
 		return -EIO;
 	}
 
-	fwver = (struct mkhi_fw_ver *)req->data;
+	rsp = (struct mkhi_msg *)buf;
+	fwver = (struct mkhi_fw_ver *)rsp->data;
 	memset(cldev->bus->fw_ver, 0, sizeof(cldev->bus->fw_ver));
 	for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++) {
 		if ((size_t)bytes_recv < MKHI_FWVER_LEN(i + 1))
@@ -329,16 +330,14 @@ static int mei_nfc_if_version(struct mei_cl *cl,
 
 	WARN_ON(mutex_is_locked(&bus->device_lock));
 
-	ret = __mei_cl_send(cl, (u8 *)&cmd, sizeof(struct mei_nfc_cmd),
-			    MEI_CL_IO_TX_BLOCKING);
+	ret = __mei_cl_send(cl, (u8 *)&cmd, sizeof(cmd), MEI_CL_IO_TX_BLOCKING);
 	if (ret < 0) {
 		dev_err(bus->dev, "Could not send IF version cmd\n");
 		return ret;
 	}
 
 	/* to be sure on the stack we alloc memory */
-	if_version_length = sizeof(struct mei_nfc_reply) +
-		sizeof(struct mei_nfc_if_version);
+	if_version_length = sizeof(*reply) + sizeof(*ver);
 
 	reply = kzalloc(if_version_length, GFP_KERNEL);
 	if (!reply)
@@ -352,7 +351,7 @@ static int mei_nfc_if_version(struct mei_cl *cl,
 		goto err;
 	}
 
-	memcpy(ver, reply->data, sizeof(struct mei_nfc_if_version));
+	memcpy(ver, reply->data, sizeof(*ver));
 
 	dev_info(bus->dev, "NFC MEI VERSION: IVN 0x%x Vendor ID 0x%x Type 0x%x\n",
 		ver->fw_ivn, ver->vendor_id, ver->radio_type);

drivers/misc/mei/bus.c

@@ -931,7 +931,7 @@ static struct mei_cl_device *mei_cl_bus_dev_alloc(struct mei_device *bus,
 	struct mei_cl_device *cldev;
 	struct mei_cl *cl;
 
-	cldev = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL);
+	cldev = kzalloc(sizeof(*cldev), GFP_KERNEL);
 	if (!cldev)
 		return NULL;