V4L/DVB (12755): af9015: improve usb control message function slightly
* define names for few values
* decrease buffer len by one byte which was not used
* add check for buffer overflow for sure
* indentation fixes
* remove useless 0 len check from memcpy
It should not happen and if it happens memcpy should not do anything.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/dvb-usb/af9015.c b/drivers/media/dvb/dvb-usb/af9015.c
index fdfa0f5..ebb9981 100644
--- a/drivers/media/dvb/dvb-usb/af9015.c
+++ b/drivers/media/dvb/dvb-usb/af9015.c
@@ -61,10 +61,13 @@
static int af9015_rw_udev(struct usb_device *udev, struct req_t *req)
{
+#define BUF_LEN 63
+#define REQ_HDR_LEN 8 /* send header size */
+#define ACK_HDR_LEN 2 /* rece header size */
int act_len, ret;
- u8 buf[64];
+ u8 buf[BUF_LEN];
u8 write = 1;
- u8 msg_len = 8;
+ u8 msg_len = REQ_HDR_LEN;
static u8 seq; /* packet sequence number */
if (mutex_lock_interruptible(&af9015_usb_mutex) < 0)
@@ -107,17 +110,26 @@
goto error_unlock;
}
+ /* buffer overflow check */
+ if ((write && (req->data_len > BUF_LEN - REQ_HDR_LEN)) ||
+ (!write && (req->data_len > BUF_LEN - ACK_HDR_LEN))) {
+ err("too much data; cmd:%d len:%d", req->cmd, req->data_len);
+ ret = -EINVAL;
+ goto error_unlock;
+ }
+
/* write requested */
if (write) {
- memcpy(&buf[8], req->data, req->data_len);
+ memcpy(&buf[REQ_HDR_LEN], req->data, req->data_len);
msg_len += req->data_len;
}
+
deb_xfer(">>> ");
debug_dump(buf, msg_len, deb_xfer);
/* send req */
ret = usb_bulk_msg(udev, usb_sndbulkpipe(udev, 0x02), buf, msg_len,
- &act_len, AF9015_USB_TIMEOUT);
+ &act_len, AF9015_USB_TIMEOUT);
if (ret)
err("bulk message failed:%d (%d/%d)", ret, msg_len, act_len);
else
@@ -130,10 +142,14 @@
if (req->cmd == DOWNLOAD_FIRMWARE || req->cmd == RECONNECT_USB)
goto exit_unlock;
- /* receive ack and data if read req */
- msg_len = 1 + 1 + req->data_len; /* seq + status + data len */
+ /* write receives seq + status = 2 bytes
+ read receives seq + status + data = 2 + N bytes */
+ msg_len = ACK_HDR_LEN;
+ if (!write)
+ msg_len += req->data_len;
+
ret = usb_bulk_msg(udev, usb_rcvbulkpipe(udev, 0x81), buf, msg_len,
- &act_len, AF9015_USB_TIMEOUT);
+ &act_len, AF9015_USB_TIMEOUT);
if (ret) {
err("recv bulk message failed:%d", ret);
ret = -1;
@@ -159,7 +175,7 @@
/* read request, copy returned data to return buf */
if (!write)
- memcpy(req->data, &buf[2], req->data_len);
+ memcpy(req->data, &buf[ACK_HDR_LEN], req->data_len);
error_unlock:
exit_unlock: