net/ixgbe: fix PF link state request size

Currently, when requesting PF link state over VF mailbox, the buffer sized
3 dwords is allocated. However, the `ixgbevf_write_msg_read_ack` function
is actually called with buffer size of 6 dwords. This leaves an admittedly
remote possibility of buffer overrun. Fix by adjusting requested size to 3.

Bugzille ID: 1801
Fixes: adbd710 ("net/ixgbe/base: fix link status for E610")
Cc: [email protected]

Signed-off-by: Andrzej Wilczynski <[email protected]>
Signed-off-by: Anatoly Burakov <[email protected]>
Acked-by: Bruce Richardson <[email protected]>

Author: awilczyx

drivers/net/intel/ixgbe/base/ixgbe_vf.c

@@ -482,7 +482,7 @@ int ixgbevf_get_pf_link_state(struct ixgbe_hw *hw, ixgbe_link_speed *speed,
 
 	msgbuf[0] = IXGBE_VF_GET_PF_LINK_STATE;
 
-	err = ixgbevf_write_msg_read_ack(hw, msgbuf, msgbuf, 6);
+	err = ixgbevf_write_msg_read_ack(hw, msgbuf, msgbuf, 3);
 	if (err || (msgbuf[0] & IXGBE_VT_MSGTYPE_FAILURE)) {
 		err = IXGBE_ERR_MBX;
 		*speed = IXGBE_LINK_SPEED_UNKNOWN;